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  • Highly uniform and nonlinear selection device based on trapezoidal band structure for high density nano-crossbar memory array
    Nano Res. (IF 7.354) Pub Date : 2017-05-06
    Qing Luo, Xiaoxin Xu, Hangbing Lv, Tiancheng Gong, Shibing Long, Qi Liu, Ling Li, Ming Liu

    Crossbar array provides a cost-effective approach for achieving high-density integration of two-terminal functional devices. However, the “sneaking current problem”, which can lead to read failure, is a severe challenge in crossbar arrays. To inhibit the sneaking current from unselected cells, the integration of individual selection devices is necessary. In this work, we report a novel TaOx-based selector exhibiting a trapezoidal band structure formed by tuning the concentration of defects in the oxide. Salient features such as a high current density (1 MA·cm–2), high selectivity (5 × 104), low off-state current (~10 pA), robust endurance (>1010), self-compliance, and excellent uniformity were successfully achieved. The integrated one-selector one-resistor (1S1R) device exhibits high nonlinearity in the low resistance state (LRS), which is quite effective in solving the sneaking current issue.

    更新日期:2017-09-09
  • Sulfur-doped graphene nanoribbons with a sequence of distinct band gaps
    Nano Res. (IF 7.354) Pub Date : 2017-07-06
    Yan-Fang Zhang, Yi Zhang, Geng Li, Jianchen Lu, Yande Que, Hui Chen, Reinhard Berger, Xinliang Feng, Klaus Müllen, Xiao Lin, Yu-Yang Zhang, Shixuan Du, Sokrates T. Pantelides, Hong-Jun Gao

    Unlike graphene sheets, graphene nanoribbons (GNRs) can exhibit semiconducting band gap characteristics that can be tuned by controlling impurity doping and the GNR widths and edge structures. However, achieving such control is a major challenge in the fabrication of GNRs. Chevron-type GNRs were recently synthesized via surface-assisted polymerization of pristine or N-substituted oligophenylene monomers. In principle, GNR heterojunctions can be fabricated by mixing two different monomers. In this paper, we report the fabrication and characterization of chevron-type GNRs using sulfur-substituted oligophenylene monomers to produce GNRs and related heterostructures for the first time. First-principles calculations show that the GNR gaps can be tailored by applying different sulfur configurations from cyclodehydrogenated isomers via debromination and intramolecular cyclodehydrogenation. This feature should enable a new approach for the creation of multiple GNR heterojunctions by engineering their sulfur configurations. These predictions have been confirmed via scanning tunneling microscopy and scanning tunneling spectroscopy. For example, we have found that the S-containing GNRs contain segments with distinct band gaps, i.e., a sequence of multiple heterojunctions that results in a sequence of quantum dots. This unusual intraribbon heterojunction sequence may be useful in nanoscale optoelectronic applications that use quantum dots.

    更新日期:2017-09-09
  • Quality assessment of graphene: Continuity, uniformity, and accuracy of mobility measurements
    Nano Res. (IF 7.354) Pub Date : 2017-07-04
    David M. A. Mackenzie, Jonas D. Buron, Patrick R. Whelan, José M. Caridad, Martin Bjergfelt, Birong Luo, Abhay Shivayogimath, Anne L. Smitshuysen, Joachim D. Thomsen, Timothy J. Booth, Lene Gammelgaard, Johanna Zultak, Bjarke S. Jessen, Peter Bøggild, Dirch H. Petersen

    With the increasing availability of large-area graphene, the ability to rapidly and accurately assess the quality of the electrical properties has become critically important. For practical applications, spatial variability in carrier density and carrier mobility must be controlled and minimized. We present a simple framework for assessing the quality and homogeneity of large-area graphene devices. The field effect in both exfoliated graphene devices encapsulated in hexagonal boron nitride and chemical vapor-deposited (CVD) devices was measured in dual current–voltage configurations and used to derive a single, gate-dependent effective shape factor, β, for each device. β is a sensitive indicator of spatial homogeneity that can be obtained from samples of arbitrary shape. All 50 devices investigated in this study show a variation (up to tenfold) in β as a function of the gate bias. Finite element simulations suggest that spatial doping inhomogeneity, rather than mobility inhomogeneity, is the primary cause of the gate dependence of β, and that measurable variations of β can be caused by doping variations as small as 1010 cm−2. Our results suggest that local variations in the position of the Dirac point alter the current flow and thus the effective sample shape as a function of the gate bias. We also found that such variations lead to systematic errors in carrier mobility calculations, which can be revealed by inspecting the corresponding β factor.

    更新日期:2017-09-09
  • An efficientfficient, controllable and facile two-step synthesis strategy: Fe 3 O 4 @RGO composites with various Fe 3 O 4 nanoparticles and their supercapacitance properties
    Nano Res. (IF 7.354) Pub Date : 2017-05-27
    Chao Lian, Zhuo Wang, Rui Lin, Dingsheng Wang, Chen Chen, Yadong Li

    An efficient, controllable, and facile two-step synthetic strategy to prepare graphene-based nanocomposites is proposed. A series of Fe3O4-decorated reduced graphene oxide (Fe3O4@RGO) nanocomposites incorporating Fe3O4 nanocrystals of various sizes were prepared by an ethanothermal method using graphene oxide (GO) and monodisperse Fe3O4 nanocrystals with diameters ranging from 4 to 10 nm. The morphologies and microstructures of the as-prepared composites were characterized by X-ray diffraction, Raman spectroscopy, nitrogen adsorption measurements, and transmission electron microscopy. The results show that GO can be reduced to graphene during the ethanothermal process, and that the Fe3O4 nanocrystals are well dispersed on the graphene sheets generated in the process. The analysis of the electrochemical properties of the Fe3O4@RGO materials shows that nanocomposites prepared with Fe3O4 nanocrystals of different sizes exhibit different electrochemical performances. Among all samples, Fe3O4@RGO prepared with Fe3O4 nanocrystals of 6 nm diameter possessed the highest specific capacitance of 481 F/g at 1 A/g, highlighting the excellent capability of this material. This work illustrates a promising route to develop graphene-based nanocomposite materials with a wide range of potential applications.

    更新日期:2017-09-09
  • Size-dependent structural and magnetic properties of chemically synthesized Co-Ni-Ga nanoparticles
    Nano Res. (IF 7.354) Pub Date : 2017-05-06
    Changhai Wang, Aleksandr A. Levin, Julie Karel, Simone Fabbrici, Jinfeng Qian, Carlos E. ViolBarbosa, Siham Ouardi, Franca Albertini, Walter Schnelle, Jan Rohlicek, Gerhard H. Fecher, Claudia Felser

    Phase transitions and magnetic properties of shape-memory materials can be tailored by tuning the size of the constituent materials, such as nanoparticles. However, owing to the lack of suitable synthetic methods for size-controlled Heusler nanoparticles, there is no report on the size dependence of their properties and functionalities. In this contribution, we present the first chemical synthesis of size-selected Co-Ni-Ga Heusler nanoparticles. We also report the structure and magnetic properties of the biphasic Co-Ni-Ga nanoparticles with sizes in the range of 30–84 nm, prepared by a SBA-15 nanoporous silicatemplated approach. The particle sizes could be readily tuned by controlling the loading and concentration of the precursors. The fractions and crystallite sizes of each phase of the Co-Ni-Ga nanoparticles are closely related to their particle size. Enhanced magnetization and decreased coercivity are observed with increasing particle size. The Curie temperature (Tc) of the Co-Ni-Ga nanoparticles also depends on their size. The 84 nm-sized particles exhibit the highest Tc (≈ 1,174 K) among all known Heusler compounds. The very high Curie temperatures of the Co-Ni-Ga nanoparticles render them promising candidates for application in high-temperature shape memory alloy-based devices.

    更新日期:2017-09-09
  • Anionic liposomes for small interfering ribonucleic acid (siRNA) delivery to primary neuronal cells: Evaluation of alpha-synuclein knockdown efficacy
    Nano Res. (IF 7.354) Pub Date : 2017-05-23
    Michele Schlich, Francesca Longhena, Gaia Faustini, Caitriona M. O’Driscoll, Chiara Sinico, Anna Maria Fadda, Arianna Bellucci, Francesco Lai

    Alpha-synuclein (α-syn) deposition in Lewy bodies (LB) is one of the main neuropathological hallmarks of Parkinson’s disease (PD). LB accumulation is considered a causative factor of PD, which suggests that strategies aimed at reducing α-syn levels could be relevant for its treatment. In the present study, we developed novel nanocarriers suitable for systemic delivery of small interfering ribonucleic acid (siRNA) that were specifically designed to reduce neuronal α-syn by RNA interference. Anionic liposomes loaded with an siRNA–protamine complex for α-syn gene silencing and decorated with a rabies virus glycoprotein (RVG)-derived peptide as a targeting agent were prepared. The nanoparticles were characterized for their ability to load, protect, and deliver the functional siRNA to mouse primary hippocampal and cortical neurons as well as their efficiency to induce gene silencing in these cells. Moreover, the nanocarriers were evaluated for their stability in serum. The RVG-decorated liposomes displayed suitable characteristics for future in vivo applications and successfully induced α-syn gene silencing in primary neurons without altering cell viability. Collectively, our results indicate that RVG-decorated liposomes may be an ideal tool for further studies aimed at achieving efficient in vivo α-syn gene silencing in mouse models of PD.

    更新日期:2017-09-09
  • Hydriding Pd cocatalysts: An approach to giant enhancement on photocatalytic CO 2 reduction into CH 4
    Nano Res. (IF 7.354) Pub Date : 2017-05-27
    Yuzhen Zhu, Chao Gao, Song Bai, Shuangming Chen, Ran Long, Li Song, Zhengquan Li, Yujie Xiong

    Photocatalytic reduction of CO2 into high value-added CH4 is a promising solution for energy and environmental crises. Integrating semiconductors with cocatalysts can improve the activities for photocatalytic CO2 reduction; however, most metal cocatalysts mainly produce CO and H2. Herein, we report a cocatalyst hydridation approach for significantly enhancing the photocatalytic reduction of CO2 into CH4. Hydriding Pd cocatalysts into PdH0.43 played a dual role in performance enhancement. As revealed by our isotopic labeling experiments, the PdH0.43 hydride cocatalysts reduced H2 evolution, which suppressed the H2 production and facilitated the conversion of the CO intermediate into the final product: CH4. Meanwhile, hydridation promoted the electron trapping on the cocatalysts, improving the charge separation. This approach increased the photocatalytic selectivity in CH4 production from 3.2% to 63.6% on Pd{100} and from 15.6% to 73.4% on Pd{111}. The results provide insights into photocatalytic mechanism studies and introduce new opportunities for designing materials towards photocatalytic CO2 conversion.

    更新日期:2017-09-09
  • Trimetallic PtRhNi alloy nanoassemblies as highly active electrocatalyst for ethanol electrooxidation
    Nano Res. (IF 7.354) Pub Date : 2017-05-27
    Huimin Liu, Jiahui Li, Lijuan Wang, Yawen Tang, Bao Yu Xia, Yu Chen

    Although nanostructures based on noble metal alloys are widely utilized in (electro)catalysis, their low-temperature synthesis remains an enormous challenge due to the different Nernst equilibrium potentials of metal precursors. Herein, we describe the successful synthesis of trimetallic PtRhNi alloy nanoassemblies (PtRhNi-ANAs) with tunable Pt/Rh ratios using a simple mixed cyanogel reduction method and provide a detailed characterization of their chemical composition, morphology, and structure. Additionally, the electrochemical properties of PtRhNi-ANAs are examined by cyclic voltammetry, revealing composition-dependent electrocatalytic activity in the ethanol oxidation reaction (EOR). Compared to a commercial Pt black electrocatalyst, optimized Pt3Rh1Ni2-ANAs display remarkably enhanced EOR electrocatalytic performance in alkaline media.

    更新日期:2017-09-09
  • Layer-by-layer assembly of long-afterglow self-supporting thin films with dual-stimuli-responsive phosphorescence and antiforgery applications
    Nano Res. (IF 7.354) Pub Date : 2017-07-04
    Rui Gao, Dongpeng Yan, David G. Evans, Xue Duan

    The assembly of thin films (TFs) having long-lasting luminescence can be expected to play an important role in the development of new-generation smart sensors, anti-counterfeiting materials, and information-encryption systems. However, such films are limited compared with their powder and solution counterparts. In this study, by exploiting the self-organization of phosphors in the two-dimensional (2D) galleries between clay nanosheets, we developed a method for the ordered assembly of long-afterglow TFs by utilizing a hydrogen-bonding layer-by-layer (LBL) process. Compared with the pristine powder, the TFs exhibit high polarization and up-conversion room-temperature phosphorescence (RTP), as well as enhanced quantum yields and luminescence lifetimes, allowing them to be used as room-temperature phosphorescent sensors for humidity and oxygen. Moreover, modified clay-based hybrids with multicolor RTP can serve as anti-counterfeiting marks and triple-mode 2D barcode displays. We anticipate that the LBL assembly process can be extended to the fabrication of other inorganic–organic room-temperature phosphorescent hybrids with smart luminescent sensor and antiforgery applications.

    更新日期:2017-09-09
  • Electrospun poly(vinylidene fluoride-trifluoroethylene)/zinc oxide nanocomposite tissue engineering scaffolds with enhanced cell adhesion and blood vessel formation
    Nano Res. (IF 7.354) Pub Date : 2017-05-06
    Robin Augustine, Pan Dan, Alejandro Sosnik, Nandakumar Kalarikkal, Nguyen Tran, Brice Vincent, Sabu Thomas, Patrick Menu, Didier Rouxel

    Piezoelectric materials that generate electrical signals in response to mechanical strain can be used in tissue engineering to stimulate cell proliferation. Poly (vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), a piezoelectric polymer, is widely used in biomaterial applications. We hypothesized that incorporation of zinc oxide (ZnO )nanoparticles into the P(VDF-TrFE) matrix could promote adhesion, migration, and proliferation of cells, as well as blood vessel formation (angiogenesis). In this study, we fabricated and comprehensively characterized a novel electrospun P(VDF-TrFE)/ZnO nanocomposite tissue engineering scaffold. We analyzed the morphological features of the polymeric matrix by scanning electron microscopy, and utilized Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry to examine changes in the crystalline phases of the copolymer due to addition of the nanoparticles. We detected no or minimal adverse effects of the biomaterials with regard to blood compatibility in vitro, biocompatibility, and cytotoxicity, indicating that P(VDF-TrFE)/ZnO nanocomposite scaffolds are suitable for tissue engineering applications. Interestingly, human mesenchymal stem cells (hMSCs) and human umbilical vein endothelial cells cultured on the nanocomposite scaffolds exhibited higher cell viability, adhesion, and proliferation compared to cells cultured on tissue culture plates or neat P(VDF-TrFE) scaffolds. Nanocomposite scaffolds implanted into rats with or without hMSCs did not elicit immunological responses, as assessed by macroscopic analysis and histology. Importantly, nanocomposite scaffolds promoted angiogenesis, which was increased in scaffolds pre-seeded with hMSCs. Overall, our results highlight the potential of these novel P(VDF-TrFE)/ZnO nanocomposites for use in tissue engineering, due to their biocompatibility and ability to promote cell adhesion and angiogenesis.

    更新日期:2017-09-09
  • Effect of interface on mid-infrared photothermal response of MoS 2 thin film grown by pulsed laser deposition
    Nano Res. (IF 7.354) Pub Date : 2017-07-04
    Ankur Goswami, Priyesh Dhandaria, Soupitak Pal, Ryan McGee, Faheem Khan, Željka Antić, Ravi Gaikwad, Kovur Prashanthi, Thomas Thundat

    This study reports on the mid-infrared (mid-IR) photothermal response of multilayer MoS2 thin films grown on crystalline (p-type silicon and c-axis-oriented single crystal sapphire) and amorphous (Si/SiO2 and Si/SiN) substrates by pulsed laser deposition (PLD). The photothermal response of the MoS2 films is measured as the changes in the resistance of the MoS2 films when irradiated with a mid-IR (7 to 8.2 μm) source. We show that enhancing the temperature coefficient of resistance (TCR) of the MoS2 thin films is possible by controlling the film-substrate interface through a proper choice of substrate and growth conditions. The thin films grown by PLD are characterized using X-ray diffraction, Raman, atomic force microscopy, X-ray photoelectron microscopy, and transmission electron microscopy. The high-resolution transmission electron microscopy (HRTEM) images show that the MoS2 films grow on sapphire substrates in a layer-by-layer manner with misfit dislocations. The layer growth morphology is disrupted when the films are grown on substrates with a diamond cubic structure (e.g., silicon) because of twin growth formation. The growth morphology on amorphous substrates, such as Si/SiO2 or Si/SiN, is very different. The PLD-grown MoS2 films on silicon show higher TCR (−2.9% K−1 at 296 K), higher mid-IR sensitivity (ΔR/R = 5.2%), and higher responsivity (8.7 V·W–1) compared to both the PLD-grown films on other substrates and the mechanically exfoliated MoS2 flakes transferred to different substrates.

    更新日期:2017-09-09
  • Electrical contacts in monolayer blue phosphorene devices
    Nano Res. (IF 7.354) Pub Date : 2017-09-08
    Jingzhen Li, Xiaotian Sun, Chengyong Xu, Xiuying Zhang, Yuanyuan Pan, Meng Ye, Zhigang Song, Ruge Quhe, Yangyang Wang, Han Zhang, Ying Guo, Jinbo Yang, Feng Pan, Jing Lu

    Semiconducting monolayer (ML) blue phosphorene (BlueP) shares similar stability with ML black phosphorene (BP), and it has recently been grown on an Au surface. Potential ML BlueP devices often require direct contact with metal to enable the injection of carriers. Using ab initio electronic structure calculations and quantum transport simulations, for the first time, we perform a systematic study of the interfacial properties of ML BlueP in contact with metals spanning a wide work function range in a field effect transistor (FET) configuration. ML BlueP has undergone metallization owing to strong interaction with five metals. There is a strong Fermi level pinning (FLP) in the ML BlueP FETs due to the metal-induced gap states (MIGS) with a pinning factor of 0.42. ML BlueP forms n-type Schottky contact with Sc, Ag, and Pt electrodes with electron Schottky barrier heights (SBHs) of 0.22, 0.22, and 0.80 eV, respectively, and p-type Schottky contact with Au and Pd electrodes with hole SBHs of 0.61 and 0.79 eV, respectively. The MIGS are eliminated by inserting graphene between ML BlueP and the metal electrode, accompanied by a transition from a strong FLP to a weak FLP. Our study not only provides insight into the ML BlueP–metal interfaces, but also helps in the design of ML BlueP devices.

    更新日期:2017-09-08
  • One-step synthesis of novel snowflake-like Si-O/Si-C nanostructures on 3D graphene/Cu foam by chemical vapor deposition
    Nano Res. (IF 7.354) Pub Date : 2017-09-08
    Jing Ning, Dong Wang, Jincheng Zhang, Xin Feng, Ruixia Zhong, Jiabo Chen, Jianguo Dong, Lixin Guo, Yue Hao

    The recent development of synthesis processes for three-dimensional (3D) graphene-based structures has tended to focus on continuous improvement of porous nanostructures, doping modification during thin-film fabrication, and mechanisms for building 3D architectures. Here, we synthesized novel snowflake-like Si-O/Si-C nanostructures on 3D graphene/Cu foam by one-step low-pressure chemical vapor deposition (CVD). Through systematic micromorphological characterization, it was determined that the formation mechanism of the nanostructures involved the melting of the Cu foam surface and the subsequent condensation of the resulting vapor, 3D growth of graphene through catalysis in the presence of Cu, and finally, nucleation of the Si-O/Si-C nanostructure in the carbon-rich atmosphere. Thus, by tuning the growth temperature and duration, it should be possible to control the nucleation and evolution of such snowflake-like nanostructures with precision. Electrochemical measurements indicated that the snowflake-like nanostructures showed excellent performance as a material for energy storage. The highest specific capacitance of the Si-O/Si-C nanostructures was ∼963.2 mF/cm2 at a scan rate of 1 mV/s. Further, even after 20,000 sequential cycles, the electrode retained 94.4% of its capacitance.

    更新日期:2017-09-08
  • Exploration of channel width scaling and edge states in transition metal dichalcogenides
    Nano Res. (IF 7.354) Pub Date : 2017-09-08
    Feng Zhang, Chia-Hui Lee, Joshua A. Robinson, Joerg Appenzeller

    We explore the impact of edge states in three types of transition metal dichalcogenides (TMDs), namely metallic Td-phase WTe2 and semiconducting 2H-phase MoTe2 and MoS2, by patterning thin flakes into ribbons with varying channel widths. No obvious charge depletion at the edges is observed for any of these three materials, in contrast to observations made for graphene nanoribbon devices. The semiconducting ribbons are characterized in a three-terminal field-effect transistor (FET) geometry. In addition, two ribbon array designs have been carefully investigated and found to exhibit current levels higher than those observed for conventional one-channel devices. Our results suggest that device structures incorporating a high number of edges can improve the performance of TMD FETs. This improvement is attributed to a higher local electric field, resulting from the edges, increasing the effective number of charge carriers, and the absence of any detrimental edge-related scattering.

    更新日期:2017-09-08
  • Triboelectrification based on double-layered polyaniline nanofibers for self-powered cathodic protection driven by wind
    Nano Res. (IF 7.354) Pub Date : 2017-09-08
    Siwen Cui, Youbin Zheng, Jun Liang, Daoai Wang

    Polyaniline nanofibers (PANI NFs) are introduced to construct a wind-driven triboelectric nanogenerator (TENG) as a new power source for self-powered cathodic protection. PANI NFs serve as a friction layer to generate charges by harvesting wind energy as well as a conducting layer to transfer charges in TENG. A PANI NFs-based TENG exhibits a high output performance with a maximum output voltage of 375 V, short current circuit of 248 μA, and corresponding power of 14.5 mW under a wind speed of 15 m/s. Additionally, a self-powered anticorrosion system is constructed by using a PANI-based TENG as the power source. The immersion experiment and electrochemical measurements demonstrate that carbon steel coupled with the wind-driven TENG is effectively protected with an evident open circuit potential drop and negative shift in the corrosion potential. The smart self-powered device is promising in terms of applications to protect metals from corrosion by utilizing wind energy in ambient conditions.

    更新日期:2017-09-08
  • Application of yolk–shell Fe 3 O 4 @N-doped carbon nanochains as highly effective microwave-absorption material
    Nano Res. (IF 7.354) Pub Date : 2017-09-08
    Mingtao Qiao, Xingfeng Lei, Yong Ma, Lidong Tian, Xiaowei He, Kehe Su, Qiuyu Zhang

    Yolk–shell Fe3O4@N-doped carbon nanochains, intended for application as a novel microwave-absorption material, have been constructed by a three-step method. Magnetic-field-induced distillation-precipitation polymerization was used to synthesize nanochains with a one-dimensional (1D) structure. Then, a polypyrrole shell was uniformly applied to the surface of the nanochains through oxidant-directed vapor-phase polymerization, and finally the pyrolysis process was completed. The obtained products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and thermogravimetric analyses (TGA) to confirm the compositions. The morphology and microstructure were observed using an optical microscope, scanning electron microscope (SEM), and transmission electron microscope (TEM). The N2 absorption–desorption isotherms indicate a Brunauer–Emmett–Teller (BET) specific surface area of 74 m2/g and a pore width of 5–30 nm. Investigations of the microwave absorption performance indicate that paraffin-based composites loaded with 20 wt.% yolk–shell Fe3O4@N-doped carbon nanochains possess a minimum reflection loss of −63.09 dB (11.91 GHz) and an effective absorption bandwidth of 5.34 GHz at a matching layer thickness of 3.1 mm. In addition, by tailoring the layer thicknesses, the effective absorption frequency bands can be made to cover most of the C, X, and Ku bands. By offering the advantages of stronger absorption, broad absorption bandwidth, low loading, thin layers, and intrinsic light weight, yolk–shell Fe3O4@N-doped carbon nanochains will be excellent candidates for practical application to microwave absorption. An analysis of the microwave absorption mechanism reveals that the excellent microwave absorption performance can be explained by the quarter-wavelength cancellation theory, good impedance matching, intense conductive loss, multiple reflections and scatterings, dielectric loss, magnetic loss, and microwave plasma loss.

    更新日期:2017-09-08
  • Mesoporous TiO 2 microparticles formed by the oriented attachment of nanocrystals: A super-durable anode material for sodium-ion batteries
    Nano Res. (IF 7.354) Pub Date : 2017-09-06
    Liming Ling, Ying Bai, Huali Wang, Qiao Ni, Jiatao Zhang, Feng Wu, Chuan Wu

    Spindle-shaped anatase TiO2 secondary particles were successfully fabricated via the oriented attachment of primary nanocrystals. By adjusting the concentration of tetrabutyl titanate, the size of the TiO2 nanocrystals and particles could be controlled, resulting in pore evolution. Pores for the random aggregation of secondary particles gradually transformed to nanopores originating from the oriented attachment of the primary nanocrystals, resulting in an excellent micro/nanostructure that increased the performance of a sodium-ion battery. The mesoporous TiO2 microparticle anode, with its unique combination of nanocrystals and uniform nanopores, displays super durability (95 mAh/g after 11,000 cycles at 1 C), high initial efficiency (61.4%), and excellent rate performance (265 and 77 mAh/g at 0.1 and 20 C, respectively). In particular, at slow discharge (0.1 C) and fast charge (5, 50, and 100 C) rates, the anatase TiO2 shows remarkable initial charge capacities of 200, 119, and 56 mAh/g, corresponding to 172, 127, and 56 mAh/g, after 150 cycles, respectively, thus meeting the requirements for fast energy storage. This excellent performance can be attributed to the stability of the material and its high ionic conductivity, resulting from the stable architecture with a mesoporous microstructure and without the random aggregation of secondary particles. A fundamental understanding of the pore structure and controllable pore construction has been proven to be effective in increasing the rate capability and durability of nanostructured electrode materials.

    更新日期:2017-09-07
  • Discharge voltage behavior of electric double-layer capacitors during high- g impact and their application to autonomously sensing high- g accelerometers
    Nano Res. (IF 7.354) Pub Date : 2017-09-06
    Keren Dai, Xiaofeng Wang, Fang Yi, Yajiang Yin, Cheng Jiang, Simiao Niu, Qingyu Li, Zheng You

    In this study, the discharge voltage behavior of electric double-layer capacitors (EDLCs) during high-g impact is studied both theoretically and experimentally. A micro-scale dynamic mechanism is proposed to describe the physical basis of the increase in the discharge voltage during a high-g impact. Based on this dynamic mechanism, a multi-field model is established, and the simulation and experimental studies of the discharge voltage increase phenomenon are conducted. From the simulation and experimental data, the relationship between the increased voltage and the high-g acceleration is revealed. An acceleration detection range of up to 10,000g is verified. The design of the device is optimized by studying the influences of the parameters, such as the electrode thickness and discharge current, on the outputs. This work opens up new avenues for the development of autonomous sensor systems based on energy storage devices and is significant for many practical applications such as in collision testing and automobile safety.

    更新日期:2017-09-07
  • Optical emission spectroscopy diagnosis of energetic Ar ions in synthesis of SiC polytypes by DC arc discharge plasma
    Nano Res. (IF 7.354) Pub Date : 2017-09-06
    Jian Gao, Lei Zhou, Jingshuang Liang, Ziming Wang, Yue Wu, Javid Muhammad, Xinglong Dong, Shouzhe Li, Hongtao Yu, Xie Quan

    Silicon carbides are basilic ceramics with proper bandgaps (2.4–3.3 eV) and unique optical properties. SiC@C monocrystal nanocapsules with different morphologies, sizes, and crystal types were synthesized via the fast and facile direct current (DC) arc discharge plasma method. The influence of Ar atmosphere on the formation of nanocrystal SiC polytypes was investigated by optical emission spectroscopy (OES) diagnoses on the arc discharge plasma. Boltzmann’s plot was used to estimate the temperatures of plasma containing different Ar concentrations as 10,582 K (in 2 × 104 Pa of Ar partial pressure) and 14,523 K (in 4 × 104 Pa of Ar partial pressure). It was found that higher energy state of plasma favors the ionization of carbon atoms and promotes the formation of α-SiC, while β-SiC is generally coexistent. Heat-treatment in air was applied to remove the carbon species in as-prepared SiC nanopowders. Thus, the intrinsic characters of SiC polytypes reappeared in the ultraviolet–visible (UV–vis) light absorbance. It was experimentally revealed that the direct bandgap of SiC is 5.72 eV, the indirect bandgap of β-SiC (3C) is 3.13 eV, and the indirect bandgap of α-SiC (6H) is 3.32 eV; visible quantum confinement effect is predicted for these polytypic SiC nanocrystals.

    更新日期:2017-09-07
  • Direct imaging and determination of the crystal structure of six-layered graphdiyne
    Nano Res. (IF 7.354) Pub Date : 2017-09-06
    Chao Li, Xiuli Lu, Yingying Han, Shangfeng Tang, Yi Ding, Ruirui Liu, Haihong Bao, Yuliang Li, Jun Luo, Tongbu Lu

    Since its discovery, the direct imaging and determination of the crystal structure of few-layer graphdiyne has proven difficult because it is too delicate under irradiation by an electron beam. In this work, the crystal structure of a six-layered graphdiyne nanosheet was directly observed by low-voltage transmission electron microscopy (TEM) using low current density. The combined use of high-resolution TEM (HRTEM) simulation, electron energy-loss spectroscopy, and electron diffraction revealed that the as-synthesized nanosheet was crystalline graphdiyne with a thickness of 2.19 nm (corresponding to a thickness of six layers) and showed ABC stacking. Thus, this work provides direct evidence for the existence and crystal structure of few-layer graphdiyne, which is a new type of two-dimensional carbon material complementary to graphene.

    更新日期:2017-09-07
  • 更新日期:2017-09-06
  • Scalable synthesis of sub-100 nm hollow carbon nanospheres for energy storage applications
    Nano Res. (IF 7.354) Pub Date : 2017-09-06
    Hongyu Zhao, Fan Zhang, Shumeng Zhang, Shengnan He, Fei Shen, Xiaogang Han, Yadong Yin, Chuanbo Gao

    None

    更新日期:2017-09-06
  • A novel method for preparing and characterizing graphene nanoplatelets/aluminum nanocomposites
    Nano Res. (IF 7.354) Pub Date : 2017-09-06
    Duosheng Li, Yin Ye, Xiaojun Liao, Qing H. Qin

    None

    更新日期:2017-09-06
  • Formation of plasmon quenching dips greatly enhances 1 O 2 generation in a chlorin e6–gold nanorod coupled system
    Nano Res. (IF 7.354) Pub Date : 2017-09-05
    Hui Zhang, Haiyun Li, Huizhen Fan, Jiao Yan, Dejing Meng, Shuai Hou, Yinglu Ji, Xiaochun Wu

    Photodynamic therapy (PDT), as a noninvasive therapeutic method, has been actively explored recently for cancer treatment. However, owing to the weak absorption in the optically transparent windows of biological tissues, most commercial photosensitizers (PSs) exhibit low singlet oxygen (1O2) quantum yields when excited by light within this window. Finding the best way to boost 1O2 production for clinical applications using light sources within this window is, thus, a great challenge. Herein, we tackle this problem using plasmon resonance energy transfer (PRET) from plasmonic nanoparticles (NPs) to PSs and demonstrate that the formation of plasmon quenching dips is an effective way to enhance 1O2 generation. The combination of the photosensitizer chlorin e6 (Ce6) and gold nanorods (AuNR) was employed as a model system. We observed a clear quenching dip in the longitudinal surface plasmon resonance (LSPR) band of the AuNRs when the LSPR band overlaps with the Q band of Ce6 and the spacing between Ce6 and the rods is within the acting distance of PRET. Upon irradiation with 660 nm continuous-wave laser light, we obtained a seven-fold enhancement in the 1O2 signal intensity compared with that of a non-PRET sample, as determined using the 1O2 electron spin resonance probe 2,2,6,6-tetramethyl-4-piperidine (TEMP). Furthermore, we demonstrated that the PRET effect is more efficient in enhancing 1O2 yield than the often-employed local field enhancement effect. The effectiveness of PRET is further extended to the in vitro level. Considering the flexibility in manipulating the localized SPR properties of plasmonic nanoparticles/nanostructures, our findings suggest that PRET-based strategies may be a general way to overcome the deficiency of most commercial organic PSs in biological optically transparent windows and promote their applications in clinical tumor treatments.

    更新日期:2017-09-05
  • Ultra-dense planar metallic nanowire arrays with extremely large anisotropic optical and magnetic properties
    Nano Res. (IF 7.354) Pub Date : 2017-09-05
    Qi Jia, Xin Ou, Manuel Langer, Benjamin Schreiber, Jörg Grenzer, Pablo F. Siles, Raul D. Rodriguez, Kai Huang, Ye Yuan, Alireza Heidarian, René Hübner, Tiangui You, Wenjie Yu, Kilian Lenz, Jürgen Lindner, Xi Wang, Stefan Facsko

    A nanofabrication method for the production of ultra-dense planar metallic nanowire arrays scalable to wafer-size is presented. The method is based on an efficient template deposition process to grow diverse metallic nanowire arrays with extreme regularity in only two steps. First, III–V semiconductor substrates are irradiated by a low-energy ion beam at an elevated temperature, forming a highly ordered nanogroove pattern by a “reverse epitaxy” process due to self-assembly of surface vacancies. Second, diverse metallic nanowire arrays (Au, Fe, Ni, Co, FeAl alloy) are fabricated on these III–V templates by deposition at a glancing incidence angle. This method allows for the fabrication of metallic nanowire arrays with periodicities down to 45 nm scaled up to wafer-size fabrication. As typical noble and magnetic metals, the Au and Fe nanowire arrays produced here exhibited large anisotropic optical and magnetic properties, respectively. The excitation of localized surface plasmon resonances (LSPRs) of the Au nanowire arrays resulted in a high electric field enhancement, which was used to detect phthalocyanine (CoPc) in surface-enhanced Raman scattering (SERS). Furthermore, the Fe nanowire arrays showed a very high in-plane magnetic anisotropy of approximately 412 mT, which may be the largest in-plane magnetic anisotropy field yet reported that is solely induced via shape anisotropy within the plane of a thin film.

    更新日期:2017-09-05
  • Interest of molecular functionalization for electrochemical storage
    Nano Res. (IF 7.354) Pub Date : 2017-09-05
    Bihag Anothumakkool, Dominique Guyomard, Joël Gaubicher, Lénaïc Madec

    Despite great interests in electrochemical energy storage systems for numerous applications, considerable challenges remain to be overcome. Among the various approaches to improving the stability, safety, performance, and cost of these systems, molecular functionalization has recently been proved an attractive method that allows the tuning of material surface reactivity while retaining the properties of the bulk material. For this purpose, the reduction of aryldiazonium salt, which is a versatile method, is considered suitable; it forms robust covalent bonds with the material surface, however, with the formation of multilayer structures and sp3 defects (for carbon substrate) that can be detrimental to the electronic conductivity. Alternatively, non-covalent molecular functionalization based on π–π interactions using aromatic ring units has been proposed. In this review, the various advances in molecular functionalization concerning the current limitations in lithium-ion batteries and electrochemical capacitors are discussed. According to the targeted applications and required properties, both covalent and non-covalent functionalization methods have proved to be very efficient and versatile. Fundamental aspects to achieve a better understanding of the functionalization reactions as well as molecular layer properties and their effects on the electrochemical performance are also discussed. Finally, perspectives are proposed for future implementation of molecular functionalization in the field of electrochemical storage.

    更新日期:2017-09-05
  • In situ transformation of Cu 2 O@MnO 2 to Cu@Mn(OH) 2 nanosheet-on-nanowire arrays for efficient hydrogen evolution
    Nano Res. (IF 7.354) Pub Date : 2017-09-05
    Li Chen, Xing Zhang, Wenjie Jiang, Yun Zhang, Linbo Huang, Yuyun Chen, Yuguo Yang, Li Li, Jinsong Hu

    The development of new non-precious metal catalysts and understanding the origin of their activity for the hydrogen evolution reaction (HER) are essential for rationally designing highly active low-cost catalysts as alternatives to state-of-the-art precious metal catalysts. Herein, manganese oxide/hydroxide was demonstrated as a highly active electrocatalysts for the HER by fabricating MnO2 nanosheets coated with Cu2O nanowire arrays (Cu2O@MnO2 NW@NS) on Cu foam followed by an in situ chronopotentiometry (CP) treatment. It was discovered that the in situ transformation of Cu2O@MnO2 into Cu@Mn(OH)2 NW@NS by the CP treatment drastically boosted the catalytic activity for the HER due to an enhancement of its intrinsic activity. Together with the benefits from such three-dimensional (3D) core–shell arrays for exposing more accessible active sites and efficient mass and electron transfers, the resulting Cu@Mn(OH)2 NW@NS exhibited excellent HER activity and outstanding durability in terms of a low overpotential of 132 mV vs. RHE at 10 mA/cm2. Overall, we expect these findings to generate new opportunities for the exploration of other Mn-based nanomaterials as efficient electrocatalysts and enable further understanding of their catalytic processes.

    更新日期:2017-09-05
  • Tunable excitonic emission of monolayer WS 2 for the optical detection of DNA nucleobases
    Nano Res. (IF 7.354) Pub Date : 2017-09-05
    Shun Feng, Chunxiao Cong, Namphung Peimyoo, Yu Chen, Jingzhi Shang, Chenji Zou, Bingchen Cao, Lishu Wu, Jing Zhang, Mustafa Eginligil, Xingzhi Wang, Qihua Xiong, Arundithi Ananthanarayanan, Peng Chen, Baile Zhang, Ting Yu

    Two-dimensional transition metal dichalcogenides (2D TMDs) possess a tunable excitonic light emission that is sensitive to external conditions such as electric field, strain, and chemical doping. In this work, we reveal the interactions between DNA nucleobases, i.e., adenine (A), guanine (G), cytosine (C), and thymine (T) and monolayer WS2 by investigating the changes in the photoluminescence (PL) emissions of the monolayer WS2 after coating with nucleobase solutions. We found that adenine and guanine exert a clear effect on the PL profile of the monolayer WS2 and cause different PL evolution trends. In contrast, cytosine and thymine have little effect on the PL behavior. To obtain information on the interactions between the DNA bases and WS2, a series of measurements were conducted on adenine-coated WS2 monolayers, as a demonstration. The p-type doping of the WS2 monolayers on the introduction of adenine is clearly shown by both the evolution of the PL spectra and the electrical transport response. Our findings open the door for the development of label-free optical sensing approaches in which the detection signals arise from the tunable excitonic emission of the TMD itself rather than the fluorescence signals of label molecules. This dopant-selective optical response to the DNA nucleobases fills the gaps in previously reported optical biosensing methods and indicates a potential new strategy for DNA sequencing.

    更新日期:2017-09-05
  • Growth of ZnO self-converted 2D nanosheet zeolitic imidazolate framework membranes by an ammonia-assisted strategy
    Nano Res. (IF 7.354) Pub Date : 2017-09-05
    Yujia Li, Lu Lin, Min Tu, Pei Nian, Ashlee J. Howarth, Omar K. Farha, Jieshan Qiu, Xiongfu Zhang

    Shaping crystalline porous materials such as metal organic frameworks (MOFs) and zeolites into two-dimensional (2D) nanosheet forms is highly desirable for developing high-performance molecular sieving membranes. However, conventional exfoliation–deposition is complex and challenging for the large-scale fabrication of nanosheet MOF tubular membranes. Here, for the first time, we report a direct growth technique by ZnO self-conversion and ammonia assistance to fabricate zeolitic imidazolate framework (ZIF) membranes consisting of 2D nanosheets on porous hollow fiber substrates; the membranes are suitable for large-scale industrial gas separation processes. The proposed fabrication process for ZIF nanosheet membranes is based on the localized self-conversion of a pre-deposited thin layer of ZnO in a ligand solution containing ammonium hydroxide as a modulator. The resulting ZIF 2D nanosheet tubular membrane is highly oriented and only 50 nm in thickness. It exhibits excellent molecular sieving performance, with high H2 permeance and selectivity for H2/CO2 separation. This technique shows great promise in MOF nanosheet membrane fabrication for large-scale molecular sieving applications.

    更新日期:2017-09-05
  • Light-powered direction-controlled micropump
    Nano Res. (IF 7.354) Pub Date : 2017-09-02
    Mingtong Li, Yajun Su, Hui Zhang, Bin Dong

    A micropump induces the flow of its surrounding fluids and is extremely promising in a variety of applications such as chemical sensing or mass transportation. However, it is still challenging to manipulate its pumping direction. In this study, we examine a binary micropump based on perovskite and poly[(2-methoxy-5-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV). The micropump is operational under the influence of light. Light exhibits significant versatility in controlling the pumping phenomenon of the micropump. It governs the start and stop and also regulates the velocity and directions. The direction control signifies immense opportunities for the development of micropumps with unprecedented pumping behaviors and functions (such as heartbeat-like pumping, rectification, and amplification). This makes them potentially useful in various fields. Hence, it is expected that the micropump reported in the current study could act as a key step towards the further development of more sophisticated micropumps for diverse applications.

    更新日期:2017-09-04
  • Mechanically robust antireflective coatings
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Sadaf Bashir Khan, Hui Wu, Xiaochen Huai, Sumeng Zou, Yuehua Liu, Zhengjun Zhang

    None

    更新日期:2017-09-04
  • 更新日期:2017-09-04
  • High-metallic-phase-concentration Mo 1–x W x S 2 nanosheets with expanded interlayers as efficient electrocatalysts
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Qun He, Yangyang Wan, Hongliang Jiang, Chuanqiang Wu, Zhongti Sun, Shuangming Chen, Yu Zhou, Haiping Chen, Daobin Liu, Yasir A. Haleem, Binghui Ge, Xiaojun Wu, Li Song

    None

    更新日期:2017-09-04
  • Improved flexible Li-ion hybrid capacitors: Techniques for superior stability
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Shengyang Dong, Hongsen Li, Junjun Wang, Xiaogang Zhang, Xiulei Ji

    None

    更新日期:2017-09-04
  • In situ carbon nanotube clusters grown from threedimensional porous graphene networks as efficient sulfur hosts for high-rate ultra-stable Li–S batteries
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Shizhi Huang, Lingli Zhang, Jingyan Wang, Jinliang Zhu, Pei Kang Shen

    None

    更新日期:2017-09-04
  • Gas template-assisted spray pyrolysis: A facile strategy to produce porous hollow Co 3 O 4 with tunable porosity for high-performance lithium-ion battery anode materials
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Haoran Du, Kuangfu Huang, Min Li, Yuanyuan Xia, Yixuan Sun, Mengkang Yu, Baoyou Geng

    None

    更新日期:2017-09-04
  • Graphene as an intermediary for enhancing the electron transfer rate: A free-standing Ni 3 S 2 @graphene@Co 9 S 8 electrocatalytic electrode for oxygen evolution reaction
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Qiuchun Dong, Yizhou Zhang, Ziyang Dai, Peng Wang, Min Zhao, Jinjun Shao, Wei Huang, Xiaochen Dong

    None

    更新日期:2017-09-04
  • Suppressed oxygen extraction and degradation of LiNi x Mn y Co z O 2 cathodes at high charge cut-off voltages
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Jianming Zheng, Pengfei Yan, Jiandong Zhang, Mark H. Engelhard, Zihua Zhu, Bryant J. Polzin, Steve Trask, Jie Xiao, Chongmin Wang, Jiguang Zhang

    None

    更新日期:2017-09-04
  • Tetrafunctional Cu 2 S thin layers on Cu 2 O nanowires for efficient photoelectrochemical water splitting
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Zhenzhen Li, Zhonghai Zhang

    None

    更新日期:2017-09-04
  • Size contrast of Pt nanoparticles formed on neighboring domains within suspended and supported graphene
    Nano Res. (IF 7.354) Pub Date : 2017-09-01
    Dario Roccella, Matteo Amati, Hikmet Sezen, Rosaria Brescia, Luca Gregoratti

    None

    更新日期:2017-09-04
  • High performance metal oxide based sensing device using an electrode with a solid/liquid/air triphase interface
    Nano Res. (IF 7.354) Pub Date : 2017-05-12
    Jun Zhang, Xia Sheng, Jian Jin, Xinjian Feng, Lei Jiang

    The wetting properties of an electrode surface are of significant importance to the performance of electrochemical devices because electron transfer occurs at the electrode/electrolyte interface. Described in this paper is a low-cost metal oxide electrocatalyst (CuO)-based high-performance sensing device using an enzyme electrode with a solid/liquid/air triphase interface in which the oxygen level is constant and sufficiently high. We apply the sensing device to detect glucose, a model test analyte, and demonstrate a linear dynamic range up to 50 mM, which is about 25 times higher than that obtained using a traditional enzyme electrode with a solid/liquid diphase interface. Moreover, we show that sensing devices based on a triphase assaying interface are insensitive to the significant oxygen level fluctuation in the analyte solution.

    更新日期:2017-08-18
  • Ag/C nanoparticles catalysed aerobic oxidation of diaryl and aryl(hetero) methylenes into ketones
    Nano Res. (IF 7.354) Pub Date : 2017-07-12
    Shuangxi Guo, Qi Zhang, Hongbo Li, Huifang Guo, Wei He

    The aerobic oxidation of diaryl and aryl(hetero) methylenes into ketones, catalyzed by Ag/C nanoparticles under mild conditions, was successfully developed. This method features a wide scope of substrates, good yields, and uncomplicated recycling of the catalyst.

    更新日期:2017-08-18
  • Carbon quantum dot-induced self-assembly of ultrathin Ni(OH) 2 nanosheets: A facile method for fabricating three-dimensional porous hierarchical composite micro-nanostructures with excellent supercapacitor performance
    Nano Res. (IF 7.354) Pub Date : 2017-05-18
    Guijuan Wei, Kun Du, Xixia Zhao, Zhaojie Wang, Ming Liu, Chuang Li, Hui Wang, Changhua An, Wei Xing

    Significant efforts have been directed towards the preparation and application of porous hierarchically structured materials owing to their large surface area, rich active sites, and enhanced mass transport and diffusion. In this study, a simple and cost-effective method for the carbon quantum dot (CQD)-induced assembly of two-dimensional ultrathin Ni(OH)2 nanosheets into a three-dimensional (3D) porous hierarchical structure was developed. The electrostatic forces between the CQDs and cations drove the self-assembly of the 3D CQDs/Ni(OH)2 hierarchical structures. As a new type of structure-directing agent, the CQDs played dual roles in tuning the morphology of the products and improving the supercapacitor performance. The multilevel CQDs/Ni(OH)2 micro-nanostructures had a large specific surface area and rich porosity. Owing to their unique structures and the conductivity of the CQDs, an optimized asymmetric supercapacitor using the CQDs/Ni(OH)2 exhibited a maximum specific capacity of 161.3 F·g–1 and a high energy density of 57.4 Wh·kg–1. This study introduces a potential method for the fabrication of many other 3D hierarchical structures with great potential for applications in various fields.

    更新日期:2017-08-18
  • MoS 2 -graphene in-plane contact for high interfacial thermal conduction
    Nano Res. (IF 7.354) Pub Date : 2017-03-27
    Xiangjun Liu, Junfeng Gao, Gang Zhang, Yong-Wei Zhang

    Recent studies have indicated that two-dimensional (2D) MoS2 exhibits low in-plane and inter-plane thermal conductivities. This poses a significant challenge to heat management in MoS2-based electronic devices. To address this challenge, we have designed MoS2-graphene interfaces that fully utilize graphene, a 2D material that exhibits very high thermal conductivity. First, we performed ab initio atomistic simulations to understand bonding and structural stability at the interfaces. The interfaces that we designed, which were connected via strong covalent bonds between Mo and C atoms, were energetically stable. We then performed molecular dynamics simulations to investigate interfacial thermal conductance in these materials. Surprisingly, the interfacial thermal conductance was high and comparable to those of covalently bonded graphene-metal interfaces. Importantly, each interfacial Mo–C bond served as an independent thermal channel, enabling modulation of the interfacial thermal conductance by controlling the Mo vacancy concentration at the interface. The present work provides a viable heat management strategy for MoS2-based electronic devices.

    更新日期:2017-08-18
  • Curved copper nanowires-based robust flexible transparent electrodes via all-solution approach
    Nano Res. (IF 7.354) Pub Date : 2017-03-24
    Zhenxing Yin, Seung Keun Song, Sanghun Cho, Duck-Jae You, Jeeyoung Yoo, Suk Tai Chang, Youn Sang Kim

    Curved Cu nanowire (CCN)-based high-performance flexible transparent conductive electrodes (FTCEs) were fabricated via a fully solution-processed approach, involving synthesis, coating, patterning, welding, and transfer. Each step involved an innovative technique for completing the all-solution processes. The high-quality and well-dispersed CCNs were synthesized using a multi-polyol method through the synergistic effect of specific polyol reduction. To precisely control the optoelectrical properties of the FTCEs, the CCNs were uniformly coated on a polyimide (PI) substrate via a simple meniscus-dragging deposition method by tuning several coating parameters. We also employed a polyurethane (PU)-stamped patterning method to effectively produce 20 μm patterns on CCN thin films. The CCN thin films exhibited high electrical performance, which is attributed to the deeply percolated CCN network formed via a solvent-dipped welding method. Finally, the CCN thin films on the PI substrate were partially embedded and transferred to the PU matrix to reduce their surface roughness. Through consecutive processes involving the proposed methods, a highly percolated CCN thin film on the PU matrix exhibited high optoelectrical performance (Rs = 53.48 Ω/□ at T = 85.71%), excellent mechanical properties (R/R0 < 1.10 after the 10th repetition of tape peeling or 1,000 bending cycles), and a low root-mean-square surface roughness (Rrms = 14.36 nm).

    更新日期:2017-08-18
  • Co-Co 3 O 4 @carbon core–shells derived from metal−organic framework nanocrystals as efficient hydrogen evolution catalysts
    Nano Res. (IF 7.354) Pub Date : 2017-04-08
    Yanyan Liu, Guosheng Han, Xiaoyu Zhang, Congcong Xing, Chenxia Du, Huaqiang Cao, Baojun Li

    Controllable pyrolysis of metal−organic frameworks (MOFs) in confined spaces is a promising strategy for the design and development of advanced functional materials. In this study, Co-Co3O4@carbon composites were synthesized via pyrolysis of a Co-MOFs@glucose polymer (Co-MOFs@GP) followed by partial oxidation of Co nanoparticles (NPs). The pyrolysis of Co-MOFs@GP generated a core–shell structure composed of carbon shells and Co NPs. The controlled partial oxidation of Co NPs formed Co-Co3O4 heterojunctions confined in carbon shells. Compared with Co-MOFs@GP and Co@carbon-n (Co@C-n), Co-Co3O4@carbon-n (Co-Co3O4@C-n) exhibited higher catalytic activity during NaBH4 hydrolysis. Co-Co3O4@C-II provided a maximum specific H2 generation rate of 5,360 mL·min−1·gCo−1 at room temperature due to synergistic interactions between Co and Co3O4 NPs. The Co NPs also endowed Co-Co3O4@C-n with the ferromagnetism needed to complete the magnetic momentum transfer process. This assembly-pyrolysis-oxidation strategy may be an efficient method of preparing novel nanocomposites.

    更新日期:2017-08-18
  • Gram-scale synthesis of nanotherapeutic agents for CT/T 1 -weighted MRI bimodal imaging guided photothermal therapy
    Nano Res. (IF 7.354) Pub Date : 2017-05-18
    Xianguang Ding, Xiaoxia Hao, Dongdong Fu, Mengxin Zhang, Tian Lan, Chunyan Li, Renjun Huang, Zhijun Zhang, Yonggang Li, Qiangbin Wang, Jiang Jiang

    Theranostic nanomedicine, which uses both imaging and therapeutic components for simultaneous disease diagnosis and treatment, is expected to improve patient treatment safety and outcomes by offering a more personalized approach to medicine. However, the poor reproducibilities of nanomedicines synthesized for optimized bioavailability and their potential toxicity are impeding clinical development. Moreover, milligram-scale synthetic methods are often inconsistent when transferred to mass production. To address these challenges, a facile, room temperature, aqueous phase synthesis of nanotheranostic agents using clinically validated mesoporous silica and naturally derived polydopamine has been developed. Since the synthetic procedure is simple and robust, and requires only simple mixing under ambient conditions, excellent batch-to-batch consistency has been achieved. As a result, this process can be easily scaled-up to produce gram-scale batches with physicochemical parameters similar to those of materials synthesized in smaller batches. The resulting nanotheranostic agents exhibit efficient X-ray tomography and T1-weighted magnetic resonance image contrast enhancing abilities due to their chemically ligated, benign Bi3+ and Fe3+ ions. Furthermore, the inclusion of a polydopamine shell makes the nanoparticle surface easy to functionalize and renders these materials highly efficient as photothermal agents. These nanotheranostic agents are suitable for mass production and for potential applications in multimodal imaging-guided therapy in clinical settings.

    更新日期:2017-08-18
  • Flower-like C@SnO X @C hollow nanostructures with enhanced electrochemical properties for lithium storage
    Nano Res. (IF 7.354) Pub Date : 2017-05-18
    Yijia Wang, Zheng Jiao, Minghong Wu, Kun Zheng, Hongwei Zhang, Jin Zou, Chengzhong Yu, Haijiao Zhang

    Hollow nanostructures have attracted considerable attention owing to their large surface area, tunable cavity, and low density. In this study, a unique flower-like C@SnOX@C hollow nanostructure (denoted as C@SnOX@C-1) was synthesized through a novel one-pot approach. The C@SnOX@C-1 had a hollow carbon core and interlaced petals on the shell. Each petal was a SnO2 nanosheet coated with an ultrathin carbon layer ~2 nm thick. The generation of the hollow carbon core, the growth of the SnO2 nanosheets, and the coating of the carbon layers were simultaneously completed via a hydrothermal process using resorcinol-formaldehyde resin-coated SiO2 nanospheres, tin chloride, urea, and glucose as precursors. The resultant architecture with a large surface area exhibited excellent lithium-storage performance, delivering a high reversible capacity of 756.9 mA·h·g–1 at a current density of 100 mA·g–1 after 100 cycles.

    更新日期:2017-08-18
  • Nanocomposite quasi-solid-state electrolyte for high-safety lithium batteries
    Nano Res. (IF 7.354) Pub Date : 2017-05-19
    Hyunji Choi, Hyun Woo Kim, Jae-Kwang Ki, Young Jun Lim, Youngsik Kim, Jou-Hyeon Ahn

    Rechargeable lithium batteries are attractive power sources for electronic devices and are being aggressively developed for vehicular use. Nevertheless, problems with their safety and reliability must be solved for the large-scale use of lithium batteries in transportation and grid-storage applications. In this study, a unique hybrid solid-state electrolyte composed of an ionic liquid electrolyte (LiTFSI/Pyr14TFSI) and BaTiO3 nanosize ceramic particles was prepared without a polymer. The electrolyte exhibited high thermal stability, a wide electrochemical window, good ionic conductivity of 1.3 × 10−3 S·cm−1 at 30 °C, and a remarkably high lithium-ion transference number of 0.35. The solid-state LiFePO4 cell exhibited the best electrochemical properties among the reported solid-state batteries, along with a reasonable rate capability. Li/LiCoO2 cells prepared using this nanocomposite solid electrolyte exhibited high performance at both room temperature and a high temperature, confirming their potential as lithium batteries with enhanced safety and a wide range of operating temperatures.

    更新日期:2017-08-18
  • Proline-derived in situ synthesis of nitrogen-doped porous carbon nanosheets with encaged Fe 2 O 3 @Fe 3 C nanoparticles for lithium-ion battery anodes
    Nano Res. (IF 7.354) Pub Date : 2017-05-15
    Jingfei Zhang, Lijuan Qi, Xiaoshu Zhu, Xiaohong Yan, Yufeng Jia, Lin Xu, Dongmei Sun, Yawen Tang

    None

    更新日期:2017-08-18
  • Biodegradable nanocarriers for small interfering ribonucleic acid (siRNA) co-delivery strategy increase the chemosensitivity of pancreatic cancer cells to gemcitabine
    Nano Res. (IF 7.354) Pub Date : 2017-05-09
    Chengbin Yang, Kok Ken Chan, Wen-Jen Lin, Alana Mauluidy Soehartono, Guimiao Lin, Huiting Toh, Ho Sup Yoon, Chih-Kuang Chen, Ken-Tye Yong

    None

    更新日期:2017-08-18
  • Folate targeted coated SPIONs as efficient tool for MRI
    Nano Res. (IF 7.354) Pub Date : 2017-05-06
    Cinzia Scialabba, Roberto Puleio, Davide Peddis, Gaspare Varvaro, Pietro Calandra, Giovanni Cassata, Luca Cicero, Mariano Licciardi, Gaetano Giammona

    The development of more sensitive diagnostic tools allowing an early-stage and highly efficient medical imaging of tumors remains a challenge. Magnetic nanoparticles seem to be the contrast agents with the highest potential, if properly constructed. Therefore, in this study, hybrid magnetic nanoarchitectures were developed using a new amphiphilic inulin-based graft copolymer (INU-LAPEG-FA) as coating material for 10-nm spinel iron oxide (magnetite, Fe3O4) superparamagnetic nanoparticles (SPION). Folic acid (FA) covalently linked to the coating copolymer in order to be exposed onto the nanoparticle surface was chosen as the targeting agent because folate receptors are upregulated in many cancer types. Physicochemical characterization and in vitro biocompatibility study was then performed on the prepared magnetic nanoparticles. The improved targeting and imaging properties of the prepared FA-SPIONs were further evaluated in nude mice using 7-Tesla magnetic resonance imaging (MRI). FA-SPIONs exhibited the ability to act as efficient contrast agents in conventional MRI, providing a potential nanoplatform not only for tumor diagnosis but also for cancer treatment, through the delivery of anticancer drug or locoregional magnetic hyperthermia.

    更新日期:2017-08-18
  • New class of two-dimensional bimetallic nanoplatelets for high energy density and electrochemically stable hybrid supercapacitors
    Nano Res. (IF 7.354) Pub Date : 2017-04-04
    Zhiting Liu, Peng Ma, Jens Ulstrup, Qijin Chi, Kake Zhu, Xinggui Zhou

    Currently, the application of supercapacitors (SCs) in portable electronic devices and vehicles is limited by their low energy density. Developing high-energy density SCs without sacrificing their advantages, such as their long-term stability and high power density, has thus become an increasing demand but a major challenge. This demand has motivated tremendous efforts, especially towards discovering and optimizing the architecture of novel electrode materials. To this end, we herein report the design, synthesis, and SC application of a new family of two-dimensional (2D) nanoplatelets, i.e., a transition-metal hydroxymethylate complex (NixCo1–x(OH)(OCH3)). Bimetallic nanoplatelets were synthesized via a cost-effective approach involving a one-step solvothermal procedure. We for the first time tuned the metal composition of these 2D nanoplatelets over the entire molar-fraction range (0–1.0). Tuning the molar ratio of Ni/Co allowed us to optimize the structures and physicochemical properties of the nanoplatelets for SC applications. When tested in a half cell, SC electrodes using the nanoplatelets exhibited high electrochemical performance with a specific capacitance as high as 1,415 F·g–1 and a 96.1% retention of the initial capacitance over 5,000 cycles. We exploited the novel 2D nanoplatelets as cathode materials to assemble a hybrid SC for full-cell tests. The resulting SCs operated in a wide potential window of 0–1.7 V, exhibited a high energy density over 50 Wh·kg–1, and sustained their performance over 10,000 charge–discharge cycles. The results suggest that the novel 2D nanoplatelets are promising alternative materials for the development of high-energy density SCs.

    更新日期:2017-08-18
  • Hierarchical Sb-Ni nanoarrays as robust binder-free anodes for high-performance sodium-ion half and full cells
    Nano Res. (IF 7.354) Pub Date : 2017-05-20
    Liying Liang, Yang Xu, Liaoyong Wen, Yueliang Li, Min Zhou, Chengliang Wang, Huaping Zhao, Ute Kaiser, Yong Lei

    A novel hierarchical electrode material for Na-ion batteries composed of Sb nanoplates on Ni nanorod arrays is developed to tackle the issues of the rapid capacity fading and poor rate capability of Sb-based materials. The three-dimensional (3D) Sb-Ni nanoarrays as anodes exhibit the synergistic effects of the two-dimensional nanoplates and the open and conductive array structure as well as strong structural integrity. Further, their capacitive behavior is confirmed through a kinetics analysis, which shows that their excellent Na-storage performance is attributable to their unique nanostructure. When used as binder-free sodium-ion battery (SIB) anodes, the nanoarrays exhibit a high capacity retention rate (more than 80% over 200 cycles) at a current density of 0.5 A·g–1 and excellent rate capacity (up to 20 A·g–1), with their capacity being 580 mAh·g–1. Moreover, a P2-Na2/3Ni1/3Mn2/3O2//3D Sb-Ni nanoarrays full cell delivers a highly reversible capacity of 579.8 mAh·g–1 over 200 cycles and an energy density as high as 100 Wh·kg–1. This design strategy for ensuring fast and stable Na storage may work with other electrode materials as well.

    更新日期:2017-08-18
  • A series of nanoparticles with phase-separated structures by 1,1-diphenylethene controlled one-step soap-free emulsion copolymerization and their application in drug release
    Nano Res. (IF 7.354) Pub Date : 2017-06-01
    Xinlong Fan, Jin Liu, Xiangkun Jia, Yin Liu, Hao Zhang, Shenqiang Wang, Baoliang Zhang, Hepeng Zhang, Qiuyu Zhang

    A facile one-step approach to synthesize various phase-separated porous, raspberry-like, flower-like, core–shell and anomalous nanoparticles and nanocapsules via 1,1-diphenylethene (DPE) controlled soap-free emulsion copolymerization of styrene (S) with glycidyl methacrylate (GMA), or acrylic acid (AA) is reported. By regulating the mass ratio of S/GMA, transparent polymer solution, porous and anomalous P(S-GMA) particles could be produced. The P(S-GMA) particles turn from flower-like to raspberry-like and then to anomalous structures with smooth surface as the increase of divinylbenzene (DVB) crosslinker. Transparent polymer solution, nanocapsules and core–shell P(S-AA) particles could be obtained by altering the mole ratio of S/AA; anomalous and raspberry-like P(S-AA) particles are produced by adding DVB. The unpolymerized S resulted from the low monomer conversion in the presence of DPE aggregates to form nano-sized droplets, and migrates towards the external surfaces of the GMA-enriched P(S-GMA) particles and the internal bulk of the AA-enriched P(S-AA) particles. The nano-sized droplets function as in situ porogen, porous P(S-GMA) particles and P(S-AA) nanocapsules are produced when the porogen is removed. This novel, facile, one-step method with excellent controllability and reproducibility will inspire new strategies for creating hierarchical phase-separated polymeric particles with various structures by simply altering the species and ratio of comonomers. The drug loading and release experiments on the porous particles and nanocapsules demonstrate that the release of doxorubicin hydrochloride is very slow in weakly basic environment and quick in weakly acidic environment, which enables the porous particles and nanocapsules with promising potential in drug delivery applications.

    更新日期:2017-08-18
  • Water-assisted self-sustained burning of metallic single-walled carbon nanotubes for scalable transistor fabrication
    Nano Res. (IF 7.354) Pub Date : 2017-07-06
    Keigo Otsuka, Taiki Inoue, Yuki Shimomura, Shohei Chiashi, Shigeo Maruyama

    Although aligned arrays of semiconducting single-walled carbon nanotubes (s-SWNTs) are promising for use in next-generation electronics owing to their ultrathin bodies and ideal electrical properties, even a small portion of metallic (m-) counterparts causes excessive leakage in field-effect transistors (FETs). To fully exploit the benefits of s-SWNTs for use in large-scale systems, it is necessary to completely eliminate m-SWNTs from as-grown SWNT arrays and thereby obtain purely semiconducting large-area arrays, wherein numerous FETs can be flexibly built. In this study, we performed electrical burning of m-SWNTs assisted by water vapor and polymer coating to eliminate m-SWNTs over a long length for the scalable fabrication of transistors from the remaining s-SWNT arrays. During the electrical-breakdown process, the combination of water vapor and the polymer coating significantly enhanced the burning of the SWNTs, resulting in a self-sustained reaction along the nanotube axis. We found that m-SWNT segments partially remaining on the anode side resulted from one-way burning from the initial breakdown position, where Joule-heating-induced oxidation first occurred. The s-SWNT-enriched arrays obtained were used to fabricate multiple FETs with a high on-off current ratio. The results indicate the advantages of this approach over conventional electrical breakdown for the large-scale purification of s-SWNTs.

    更新日期:2017-08-18
  • Unexpected elastic isotropy in a black phosphorene/TiC 2 van der Waals heterostructure with flexible Li-ion battery anode applications
    Nano Res. (IF 7.354) Pub Date : 2017-05-19
    Qiong Peng, Kangming Hu, Baisheng Sa, Jian Zhou, Bo Wu, Xianhua Hou, Zhimei Sun

    Recently, flexible electrodes with biaxial/omnidirectional stretchability have attracted significant attention. However, most existing pliable electrode materials can be only stretched in one direction. In this work, an unexpected isotropic van der Waals (vdW) heterostructure is proposed, based on the assembly of two-dimensional crystals of anisotropic black phosphorene (BP) and transition metal carbide (TiC2). Using vdW-corrected density functional theory calculations, the BP/TiC2 vdW heterostructure was predicted to have excellent structural and mechanical stability, superior electrical conductivity, omnidirectional flexibility, and a high Li storage capacity. We have unraveled the physical origin of the excellent stability, as well as the Li adsorption preferences of the lithiated heterostructure, based on a three-step analysis of the stability of the Li-adsorption processes. In addition, the BP/TiC2 vdW heterostructure can also be applied as the anode material for flexible Na-ion batteries because of its high Na storage capacity and strong Na binding. However, compared with Na adsorption, the capacity is higher, and the adsorption energy is more negative for Li adsorption. Our findings provide valuable insights into the exploration of a rich variety of vdW heterostructures for next-generation flexible energy storage devices.

    更新日期:2017-08-18
  • Strain-induced band gap engineering in layered TiS 3
    Nano Res. (IF 7.354) Pub Date : 2017-08-17
    Robert Biele, Eduardo Flores, Jose Ramón Ares, Carlos Sanchez, Isabel J. Ferrer, Gabino Rubio-Bollinger, Andres Castellanos-Gomez, Roberto D’Agosta

    By combining ab initio calculations and experiments, we demonstrate how the band gap of the transition metal trichalcogenide TiS3 can be modified by inducing tensile or compressive strain. In addition, using our calculations, we predicted that the material would exhibit a transition from a direct to an indirect band gap upon application of a compressive strain in the direction of easy electrical transport. The ability to control the band gap and its nature could have a significant impact on the use of TiS3 for optical applications. We go on to verify our prediction via optical absorption experiments that demonstrate a band gap increase of up to 9% (from 0.99 to 1.08 eV) upon application of tensile stress along the easy transport direction.

    更新日期:2017-08-17
  • Engineering carbon quantum dots for photomediated theranostics
    Nano Res. (IF 7.354) Pub Date : 2017-08-17
    Mahbub Hassan, Vincent G. Gomes, Alireza Dehghani, Sara M. Ardekani

    Carbon quantum dots (CQDs) have emerged as potential alternatives to classical metal-based semiconductor quantum dots (QDs) due to the abundance of their precursors, their ease of synthesis, high biocompatibility, low cost, and particularly their strong photoresponsiveness, tunability, and stability. Light is a versatile, tunable stimulus that can provide spatiotemporal control. Its interaction with CQDs elicits interesting responses such as wavelength-dependent optical emissions, charge/electron transfer, and heat generation, processes that are suitable for a range of photomediated bioapplications. The carbogenic core and surface characteristics of CQDs can be tuned through versatile engineering strategies to endow specific optical and physicochemical properties, while conjugation with specific moieties can enable the design of targeted probes. Fundamental approaches to tune the responses of CQDs to photo-interactions and the design of bionanoprobes are presented, which enable biomedical applications involving diagnostics and therapeutics. These strategies represent comprehensive platforms for engineering multifunctional probes for nanomedicine, and the design of QD probes with a range of metal-free and emerging 2D materials.

    更新日期:2017-08-17
  • Atomic disorders in layer structured topological insulator SnBi 2 Te 4 nanoplates
    Nano Res. (IF 7.354) Pub Date : 2017-08-17
    Yi-Chao Zou, Zhi-Gang Chen, Enze Zhang, Fantai Kong, Yan Lu, Lihua Wang, John Drennan, Zhongchang Wang, Faxian Xiu, Kyeongjae Cho, Jin Zou

    Identification of atomic disorders and their subsequent control has proven to be a key issue in predicting, understanding, and enhancing the properties of newly emerging topological insulator materials. Here, we demonstrate direct evidence of the cation antisites in single-crystal SnBi2Te4 nanoplates grown by chemical vapor deposition, through a combination of sub-ångström-resolution imaging, quantitative image simulations, and density functional theory calculations. The results of these combined techniques revealed a recognizable amount of cation antisites between Bi and Sn, and energetic calculations revealed that such cation antisites have a low formation energy. The impact of the cation antisites was also investigated by electronic structure calculations together with transport measurement. The topological surface properties of the nanoplates were further probed by angle-dependent magnetotransport, and from the results, we observed a two-dimensional weak antilocalization effect associated with surface carriers. Our approach provides a pathway to identify the antisite defects in ternary chalcogenides and the application potential of SnBi2Te4 nanostructures in next-generation electronic and spintronic devices.

    更新日期:2017-08-17
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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