Monodisperse nitrogen-doped carbon nanospheres were synthesized and loaded onto graphitic carbon nitride and the composites show outstanding photocatalytic activity. Improved sulfachloropyridazine degradation is consistent with density functional theory calculation..

Multifunctional TiO2 nanostructures hold promise for advancing a wide range of biomedical applications due to a feasible integration of distinct theranostic features. Fabrication and post-fabrication strategies implemented to generate multifunctional TiO2 nanostructures for a broad range of biomedical applications are briefly outlined. The opportunities and challenges of TiO2 nanomaterials are highlighted in order to open the possibility of clinical translation.

The electrical transport of the metallized vein networks is mimicked from the material transport function of the leaf vein networks. The vein-like transparent conducting electrodes show ultralow sheet resistance < 0.1 Ω □−1, broadband optical transparency > 80%, and high current density transport capability > 6000 A cm−2. The metal consumption for the metallization of the leaf veins can be as low as 4 g m−2.

All the important single-atom catalysts (SACs) synthetic strategies, such as wet-chemistry method, atomic layer deposition, metal–organic framework-derived method, electrodeposition, high-temperature atom trapping from bulk particles, and vacancies/defects immobilized strategy, have been summarized and discussed in detail. Various metal-based (especially Pt, Pd, Ru, Fe, Co, Ni, Mo, W, V) SACs in electrocatalytic hydrogen evolution reaction (HER) have been systematically reviewed. The current key challenges in SACs for electrochemical HER are pointed out, and some potential strategies/perspectives are proposed.

Hierarchical N-doped porous carbons (NPCs) with large surface area and controllable N-doping are synthesized by ball milling, followed by pyrolysis.

Flower-like CeO2 nanoparticles enhance the performance of CuO nanoparticle/Cu.

Hierarchical porous reduced graphene oxide/poly(3,4-ethylenedioxythiophene)/polyaniline hybrid was designed. The hybrid achieves a high capacitance of 535 F g−1 along with a good rate capability and cyclability.

The scalable graphitic carbon quantum dots (CQDs) are obtained with a high yield of more than 50%. The CQDs are utilized to synthesize novel NS-CQDs/NiCo2S4 composite which shows enhanced electrochemical properties. The assembled novel alkaline aqueous battery delivers superior electrochemical performances.

The reaction mechanism of various kinds of nanomaterials with endogenous H2O2 is outlined. The design and application guideline for various H2O2-responsive nanomaterials in photodynamic therapy (PDT) are reviewed. The development and prospect of various H2O2-response nanomaterials for PDT and clinical application are envisioned.

Highly crystalline Mn2O3 materials with tunable pore sizes are obtained and employed as high-performance cathode materials for reversible aqueous Zn-ion battery. The Zn/Mn2O3 battery exhibits significantly improved rate capability and remarkable cycling durability due to the introduction of nanoporous architecture. The Zn2+/H+ intercalations mechanism is put forward for the Zn/Mn2O3 battery.

An energy harvesting textile with an elegant trade-off of mechanical and triboelectric performance was constructed by hierarchical structural design. Modified rotor co-spinning technique was developed to produce triboelectric yarns in large scale. Mass-producible energy harvesting textiles show ultrahigh stability withstands millions of multi-type cyclic deformations and various applications.

Recent advances of micro/nanomotors in the field of cancer-targeted delivery, diagnosis, and imaging-guided therapy are summarized. Challenges and outlook for the future development of micro/nanomotors toward clinical applications are discussed.

Establish processing-composition-microstructure-property relationships governing binderless tungsten carbide (BTC). Highlight the densification improving strategies and toughening methods for BTC. Provide key challenges as well as the outlook for superior peformance associated with BTC.

K2Ti6O13 nanoparticle (KTO NP)-loaded porous reduced graphene oxide crumples (PGCs) were fabricated. The specific capacitance was improved due to the synergy effect between KTO and PGC. The KTO NP/PGC composites can be promising electrode materials for supercapacitors.

The study reveals the great potential of metal–organic framework (MOF)-based nanocomposites in thermal insulation and fire retardancy applications. A nanoengineering approach was developed to process MOFs into freestanding, mechanically strong, and elastic aerogels, which may boost the fundamental research and practical applications of MOFs in these areas.

Experimental and density functional theory studies were performed for Au decorated WO3/g-C3N4 Z-scheme heterojunction.

The 1T-WS2@TiO2@Ti3C2 photocatalyst is highly active for water splitting to produce hydrogen at 3409.8 μmol g−1 h−1. The Ti3C2 MXene and octahedral (1T) phase WS2 act pathways transferring photogenerated electrons.

A power generator based on carbon nanoparticles and TiO2 nanowires was fabricated by sequential electrophoretic deposition.

Electronic waste Cu wires were successfully used as a cost-effective current collector for high-energy wire-type rechargeable alkaline batteries. The scalable approach was applied to reduce, reuse, and recycle electronic waste. A developed wire-type rechargeable alkaline battery exhibited a high-energy-density of 82.42 Wh kg−1 with long-term cycling stability.

Confined space/water in graphene hydrogel was constructed and controlled. Adsorption capacity of porous adsorbents was enhanced by filling confined water. Incomplete hydrogen bonding in confined water contributes to adsorption.

N-Ti3C2@CNT microspheres are successfully synthesized by the simple spray drying and one-step pyrolysis. Within the microsphere, MXene nanosheets intimately interact with CNTs constructing porous and highly conductive network, which can provide strong immobilization for polysulfides. N-Ti3C2@CNT microsphere/S cathode shows highly cycling stability in lithium-sulfur battery.

The superior conductivity and unique porous electrode structure in the TiN paper enable fast charging by simultaneously providing efficient ion diffusion and electron transport.

Carboxylated C60 may be considered a novel antioxidant agent to be used as a semen extender supplement for assisted reproductive technology.

Different approaches for efficient carbon-free energy from water splitting are summarized. Step-wise evolution of water splitting research is highlighted with current progress. It describes the open challenges of charge transport properties and future research direction.

Single-atom Co–MoS2 (SA Co–MoS2) is prepared successfully to serve as a proof-of-concept nanozyme model, which exhibits peroxidase-like performance comparable to that of natural enzymes. The different mechanisms between the single-atom metal center and the support are investigated experimentally and theoretically.

Nanocube-like KNiFe(CN)6 and rugby ball-like NaTi2(PO4)3 are grown on carbon nanotube fibers via simple and mild methods. A quasi-solid-state fiber-shaped aqueous rechargeable sodium-ion battery based on all binder-free electrodes is successfully assembled for the first time, delivering a high volumetric capacity of 34.21 mAh cm−3 and impressive volumetric energy density of 39.32 mWh cm−3. The device delivers superior mechanical flexibility with only 5.7% of initial capacity loss after bending at 90° for over 3000 cycles.

A simple method to prepare flexible hydrophobic smart coatings was proposed.

The recent progress on using cell membrane-coated nanoparticles for drug delivery, cancer treatment, vascular disease, immune modulation, and detoxification are summarized in this review. The patent applications related to the cell membrane coating technology from the past 10 years are collected, the future challenges and trends pertaining to this technology are comprehensively discussed. Unique properties of cell membrane-coated nanoparticles make it a promising strategy for biomedical applications and will make outstanding contributions to human health.

The main components, principle, and technology of dielectric elastomer actuator (DEA) were reviewed to illustrate that DEA can be an effective carrier for mechanobiology research. Comparison between DEA-based bioreactors and current commercial devices is provided, as well as the outlook of the DEA bio-applications in the future.

Reduced graphene oxide (rGO) in electrode can weaken the light scattering of plasmonic Ag nanoparticles and promote the hot electrons transfer from Ag nanoparticles to Ti substrate. A route synergizing rGO with plasmonic Ag on TiO2 for plasmonic solar water splitting was provided.

Metallic cobalt selenide quantum dots encapsulated in mesoporous carbon matrix were prepared via a direct hydrothermal method.

This work starts the research of pseudocapacitive oxide materials for multivalent Zn2+ storage. The constructed RuO2·H2O||Zn systems exhibit outstanding electrochemical performance, including a high discharge capacity, ultrafast charge/discharge capability, and excellent cycling stability. The redox pseudocapacitive behavior of RuO2·H2O for Zn2+ storage is revealed.

Titania-coated Au nanobipyramids (NBP@TiO2) with a high photothermal conversion efficiency in the NIR-II window are synthesized. The TiO2 shell is capable for the loading of the anticancer drug combretastatin A-4 phosphate (CA4P). The CA4P-loaded NBP@TiO2 nanostructures subjected with photothermal therapy induce synergistic anticancer and antiangiogenesis effects under 1064-nm laser irradiation at a power density lower than the skin tolerance threshold value.

[This corrects the article DOI: 10.1007/s40820-015-0068-y.].

[This corrects the article DOI: 10.1007/s40820-015-0046-4.].

We developed novel hybrid ligands to passivate PbS colloidal quantum dots (CQDs), and two kinds of solar cells based on as-synthesized CQDs were fabricated to verify the passivation effects of the ligands. It was found that the ligands strongly affected the optical and electrical properties of CQDs, and the performances of solar cells were enhanced strongly. The optimized hybrid ligands, oleic amine/octyl-phosphine acid/CdCl2 improved power conversion efficiency (PCE) to much higher of 3.72 % for Schottky diode cell and 5.04 % for p-n junction cell. These results may be beneficial to design passivation strategy for low-cost and high-performance CQDs solar cells.

Here, large-scale and uniform hexagonal zinc oxide (ZnO) nanosheet films were deposited onto indium tin oxide (ITO)-coated transparent conducting glass substrates via a facile galvanic displacement deposition process. Compared with other commonly used solution methods, this process avoids high temperature and electric power as well as supporting agents to make it simple and cost-effective. The as-fabricated ZnO nanosheet films have uniform hexagonal wurtzite structure. The photoelectrochemical (PEC) cell based on ZnO nanosheet film/ITO photoelectrode was also fabricated and its performance was improved by optimizing the solution concentration. A higher photocurrent density of ~500 μA cm-2 under AM 1.5 G simulated illumination of 100 mW cm-2 with zero bias potential (vs. Ag/AgCl electrode) was obtained, which may ascribe to the increased surface-to-volume ratio of disordered ZnO nanosheet arrays. Our developed method may be used to deposit other oxide semiconductors, and the ZnO nanosheet film/ITO PEC cell can be used to design low-cost optoelectronic and photoelectrochemical devices.

Surface acoustic wave (SAW) devices have been utilized for the sensing of chemical and biological phenomena in microscale for the past few decades. In this study, SAW device was fabricated by electrospinning poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) incorporated with zinc oxide (ZnO) nanoparticles over the delay line area of the SAW device. The morphology, composition, and crystallinity of P(VDF-TrFE)/ZnO nanocomposites were investigated. After measurement of SAW frequency response, it was found that the insertion loss of the SAW devices incorporated with ZnO nanoparticles was much less than that of the neat polymer-deposited device. The fabricated device was expected to be used in acoustic biosensors to detect and quantify the cell proliferation in cell culture systems.

Silver (Ag) nanostructures demonstrate outstanding optical, electrical, magnetic, and catalytic properties and are utilized in photonic, energy, sensors, and biomedical devices. The target application and the performance can be inherently tuned by control of configuration, shape, and size of Ag nanostructures. In this work, we demonstrate the systematical fabrication of various configurations of Ag nanostructures on sapphire (0001) by controlling the Ag deposition thickness at different annealing environments in a plasma ion coater. In particular, the evolution of Ag particles (between 2 and 20 nm), irregular nanoclusters (between 30 and 60 nm), and nanocluster networks (between 80 and 200 nm) are found be depended on the thickness of Ag thin film. The results were systematically analyzed and explained based on the solid-state dewetting, surface diffusion, Volmer-Weber growth model, coalescence, and surface energy minimization mechanism. The growth behavior of Ag nanostructures is remarkably differentiated at higher annealing temperature (750 °C) due to the sublimation and temperature-dependent characteristic of dewetting process. In addition, Raman and reflectance spectra analyses reveal that optical properties of Ag nanostructures depend on their morphology.

Abstract A significant promotion effect of low-molecular hydroxyl compounds (LMHCs) was found in the nano-photoelectrocatalytic (NPEC) degradation of fulvic acid (FA), which is a typical kind of humic acid existing widely in natural water bodies, and its influence mechanism was proposed. A TiO2 nanotube arrays (TNAs) material is served as the photoanode. Methanol, ethanediol, and glycerol were chosen as the representative of LMHCs in this study. The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value. The adsorption constants of FA, methanol, ethanediol, and glycerol were 43.44, 19.32, 7.00, and 1.30, respectively, which indicates that FA has the strongest adsorption property. The degradation performance of these organics and their mixture were observed in a thin-layer reactor. It shows that FA could hardly achieve exhausted mineralization alone, while LMHCs could be easily oxidized completely in the same condition. The degradation degree of FA, which is added LMHCs, improves significantly and the best promotion effect is achieved by glycerol. The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process. The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products. Among the chosen LMHCs, glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion. This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water. Graphical Abstract

The inhibition effect of tert-butyl alcohol (TBA), identified as the •OH radical inhibitor, on the TiO2 nano assays (TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was reported. The adsorption performance of these organics on the TNA photoelectrode was investigated by using the instantaneous photocurrent value, and the degradation property was examined by using the exhausted reaction. The results showed that glucose exhibited the poor adsorption and easy degradation performance, phthalate showed the strong adsorption and hard-degradation, but TBA showed the weak adsorption and was the most difficult to be degraded. The degradation of both glucose and phthalate could be inhibited evidently by TBA. But the effect on glucose was more obvious. The different inhibition effects of TBA on different organics could be attributed to the differences in the adsorption and the degradation property. For instance, phthalate of the strong adsorption property could avoid from the capture of •OH radicals by TBA in TNA photoelectrocatalytic process.

An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their environments: some 10 million living prototypes (i.e., estimated number of existing plants and animals) for engineers. The complexity of the hierarchical structures and their functionality in biological organisms surpasses all abiotic natural surfaces: even superhydrophobicity is restricted in nature to living organisms and was probably a key evolutionary step with the invasion of terrestrial habitats some 350-450 million years ago in plants and insects. Special attention should be paid to the fact that global environmental change implies a dramatic loss of species and with it the biological role models. Plants, the dominating group of organisms on our planet, are sessile organisms with large multifunctional surfaces and thus exhibit particular intriguing features. Superhydrophilicity and superhydrophobicity are focal points in this work. We estimate that superhydrophobic plant leaves (e.g., grasses) comprise in total an area of around 250 million km2, which is about 50% of the total surface of our planet. A survey of structures and functions based on own examinations of almost 20,000 species is provided, for further references we refer to Barthlott et al. (Philos. Trans. R. Soc. A 374: 20160191, 1). A basic difference exists between aquatic non-vascular and land-living vascular plants; the latter exhibit a particular intriguing surface chemistry and architecture. The diversity of features is described in detail according to their hierarchical structural order. The first underlying and essential feature is the polymer cuticle superimposed by epicuticular wax and the curvature of single cells up to complex multicellular structures. A descriptive terminology for this diversity is provided. Simplified, the functions of plant surface characteristics may be grouped into six categories: (1) mechanical properties, (2) influence on reflection and absorption of spectral radiation, (3) reduction of water loss or increase of water uptake, moisture harvesting, (4) adhesion and non-adhesion (lotus effect, insect trapping), (5) drag and turbulence increase, or (6) air retention under water for drag reduction or gas exchange (Salvinia effect). This list is far from complete. A short overview of the history of bionics and the impressive spectrum of existing and anticipated biomimetic applications are provided. The major challenge for engineers and materials scientists, the durability of the fragile nanocoatings, is also discussed.

Abstract Magnetic hyperthermia is a fast emerging, non-invasive cancer treatment method which is used synergistically with the existing cancer therapeutics. We have attempted to address the current challenges in clinical magnetic hyperthermia-improved biocompatibility and enhanced heating characteristics, through a single combinatorial approach. Both superparamagnetic iron oxide nanoparticles (SPIONs) of size 10 nm and ferrimagnetic iron oxide nanoparticles (FIONs) of size 30 nm were synthesized by thermal decomposition method for comparison studies. Two different surface modifying agents, viz, Cetyl Trimethyl Ammonium Bromide and 3-Aminopropyltrimethoxysilane, were used to conjugate Bovine Serum Albumin (BSA) over the iron oxide nanoparticles via two different methods-surface charge adsorption and covalent amide bonding, respectively. The preliminary haemolysis and cell viability experiments show that BSA conjugation mitigates the haemolytic effect of the iron oxide nanoparticles on erythrocytes and is non-cytotoxic to the healthy Baby Hamster Kidney cells. It was observed from the results that due to better colloidal stability, the SAR value of the BSA-iron oxide nanoparticles is higher than the iron oxide nanoparticles without BSA, irrespective of the size of the iron oxide nanoparticles and method of conjugation. The BSA-FIONs seem to show improved biocompatibility, as the haemolytic index is less than 2 % and cell viability is up to 120 %, when normalized with the control. The SAR value of BSA-FIONs is 2300 W g-1 when compared to 1700 W g-1 of FIONs without BSA conjugation. Thus, we report here that BSA conjugation over FIONs (with a high saturation magnetization of 87 emu g-1) provide a single combinatorial approach to improve the biocompatibility and enhance the SAR value for magnetic hyperthermia, thus addressing both the current challenges of the same. Graphical Abstract

Recently, two-dimensional monolayer molybdenum disulfide (MoS2), a transition metal dichalcogenide, has received considerable attention due to its direct bandgap, which does not exist in its bulk form, enabling applications in optoelectronics and also thanks to its enhanced catalytic activity which allows it to be used for energy harvesting. However, growth of controllable and high-quality monolayers is still a matter of research and the parameters determining growth mechanism are not completely clear. In this work, chemical vapor deposition is utilized to grow monolayer MoS2 flakes while deposition duration and temperature effect have been systematically varied to develop a better understanding of the MoS2 film formation and the influence of these parameters on the quality of the monolayer flakes. Different from previous studies, SEM results show that single-layer MoS2 flakes do not necessarily grow flat on the surface, but rather they can stay erect and inclined at different angles on the surface, indicating possible gas-phase reactions allowing for monolayer film formation. We have also revealed that process duration influences the amount of MoO3/MoO2 within the film network. The homogeneity and the number of layers depend on the change in the desorption-adsorption of radicals together with sulfurization rates, and, inasmuch, a careful optimization of parameters is crucial. Therefore, distinct from the general trend of MoS2 monolayer formation, our films are rough and heterogeneous with monolayer MoS2 nanowalls. Despite this roughness and the heterogeneity, we observe a strong photoluminescence located around 675 nm.

It has been revealed that the different morphologies of anodized TiO2 nanotubes, especially nanotube diameters, triggered different cell behaviors. However, the influence of TiO2 nanotubes with coexisting multi-size diameters on cell behaviors is seldom reported. In this work, coexisting four-diameter TiO2 nanotube samples, namely, one single substrate with the integration of four different nanotube diameters (60, 150, 250, and 350 nm), were prepared by repeated anodization. The boundaries between two different diameter regions show well-organized structure without obvious difference in height. The adhesion behaviors of MC3T3-E1 cells on the coexisting four-diameter TiO2 nanotube arrays were investigated. The results exhibit a significant difference of cell density between smaller diameters (60 and 150 nm) and larger diameters (250 and 350 nm) within 24 h incubation with the coexistence of different diameters, which is totally different from that on the single-diameter TiO2 nanotube arrays. The coexistence of four different diameters does not change greatly the cell morphologies compared with the single-diameter nanotubes. The findings in this work are expected to offer further understanding of the interaction between cells and materials.

Realizing the uniform dispersion of nanocarbons such as carbon nanotube and graphene in metals, is an essential prerequisite to fully exhibit their enhancement effect in mechanical, thermal, and electrical properties of metal matrix composites (MMCs). In this work, we propose an effective method to achieve uniform distribution of nanocarbons in various metal flakes through a slurry-based method. It relies on the electrostatic interactions between the negatively charged nanocarbons and the positively charged metal flakes when mixed in slurry. For case study, flake metal powders (Al, Mg, Ti, Fe, and Cu) were positively charged in aqueous suspension by spontaneous ionization or cationic surface modification. While nanocarbons, given examples as carboxylic multi-walled carbon nanotubes, pristine single-walled carbon nanotube, and carbon nanotube-graphene oxide hybrid were negatively charged by the ionization of oxygen-containing functional groups or anionic surfactant. It was found that through the electrostatic interaction mechanism, all kinds of nanocarbons can be spontaneously and efficiently adsorbed onto the surface of various metal flakes. The development of such a versatile method would provide us great opportunities to fabricate advanced MMCs with appealing properties.

Gold nanoparticles (GNPs) are emerging as a novel tool to improve existing cancer therapeutics. GNPs are being used as radiation dose enhancers in radiation therapy as well as anticancer drugs carriers in chemotherapy. However, the success of GNP-based therapeutics depends on their ability to penetrate tumor tissue. GNPs of 20 and 50 nm diameters were used to elucidate the effects of size on the GNP interaction with tumor cells at monolayer and multilayer level. At monolayer cell level, smaller NPs had a lower uptake compared to larger NPs at monolayer cell level. However, the order was reversed at tissue-like multilayer level. The smaller NPs penetrated better compared to larger NPs in tissue-like materials. Based on our study using tissue-like materials, we can predict that the smaller NPs are better for future therapeutics due to their greater penetration in tumor tissue once leaving the leaky blood vessels. In this study, tissue-like multilayer cellular structures (MLCs) were grown to model the post-vascular tumor environment. The MLCs exhibited a much more extensive extracellular matrix than monolayer cell cultures. The MLC model can be used to optimize the nano-micro interface at tissue level before moving into animal models. This would accelerate the use of NPs in future cancer therapeutics.

In this study, a nanobiosensor for detecting explosives was developed, in which the peptide was synthesized with trinitrotoluene (TNT)-specific sequence and immobilized on nanodevice by Au-S covalent linkage, and the nanocup arrays were fabricated by nanoimprint and deposited with Au nanoparticles to generate localized surface plasmon resonance (LSPR). The device was used to monitor slight change from specific binding of 2,4,6-TNT to the peptide. With high refractive index sensing of ~104 nm/RIU, the nanocup device can detect the binding of TNT at concentration as low as 3.12 × 10-7 mg mL-1 by optical transmission spectrum modulated by LSPR. The nanosensor is also able to distinguish TNT from analogs of 2,4-dinitrotoluene and 3-nitrotoluene in the mixture with great selectivity. The peptide-based nanosensor provides novel approaches to design versatile biosensor assays by LSPR for chemical molecules.

InGaAs is an important bandgap-variable ternary semiconductor which has wide applications in electronics and optoelectronics. In this work, single-crystal InGaAs nanowires were synthesized by a chemical vapor deposition method. Photoluminescence measurements indicate the InGaAs nanowires have strong light emission in near-infrared region. For the first time, photodetector based on as-grown InGaAs nanowires was also constructed. It shows good light response over a broad spectral range in infrared region with responsivity of 6.5 × 103 A W-1 and external quantum efficiency of 5.04 × 105 %. This photodetector may have potential applications in integrated optoelectronic devices and systems.

In this paper, high-quality nanocrystalline SnO2 thin film was grown on bare Si (100) substrates by a sol-gel method. A metal-semiconductor-metal gas sensor was fabricated using nanocrystalline SnO2 thin film and palladium (Pd) metal. The contact between Pd and nanocrystalline SnO2 film is tunable. Ohmic barrier contact was formed without addition of glycerin, while Schottky contact formed by adding glycerin. Two kinds of sensor devices with Schottky contact were fabricated (Device 1: 8 h, 500 °C; Device 2: 10 h, 400 °C). The room temperature sensitivity for hydrogen (H2) was 120 and 95 % in 1000 ppm H2, and the low power consumption was 65 and 86 µW for two devices, respectively. At higher temperature of 125 °C, the sensitivity was increased to 195 and 160 %, respectively. The sensing measurements were repeatable at various temperatures (room temperature, 75, 125 °C) for over 50 min. It was found that Device 1 has better sensitivity than Device 2 due to its better crystallinity. These findings indicate that the sensors fabricated on bare Si by adding glycerin to the sol solution have strong ability to detect H2 gas under different concentrations and temperatures.

Ceria (CeO2) nanocubes were synthesized by a hydrothermal method and weak ferromagnetism was observed in room temperature. After ultraviolet irradiation, the saturation magnetization was significantly enhanced from ~3.18 × 10-3 to ~1.89 × 10-2 emu g-1. This is due to the increase of oxygen vacancies in CeO2 structure which was confirmed by X-ray photoelectron spectra. The first-principle calculation with Vienna ab-initio simulation package was used to illustrate the enhanced ferromagnetism mechanism after calculating the density of states (DOSs) and partial density of states (PDOSs) of CeO2 without and with different oxygen vacancies. It was found that the increase of oxygen vacancies will enlarge the PDOSs of Ce 4f orbital and DOSs. Two electrons in one oxygen vacancy are respectively excited to 4f orbital of two Ce atoms neighboring the vacancy, making these electron spin directions on 4f orbitals of these two Ce atoms parallel. This superexchange interaction leads to the formation of ferromagnetism in CeO2 at room temperature. Our work indicates that ultraviolet irradiation is an effective method to enhance the magnetism of CeO2 nanocube, and the first-principle calculation can understand well the enhanced magnetism.

Photoelectrochemical (PEC) water splitting using solar energy has attracted great attention for generation of renewable hydrogen with less carbon footprint, while there are enormous challenges that still remain for improving solar energy water splitting efficiency, due to limited light harvesting, energy loss associated to fast recombination of photogenerated charge carriers, as well as electrode degradation. This overview focuses on the recent development about catalyst nanomaterials and nanostructures in different PEC water splitting systems. As photoanode, Au nanoparticle-decorated TiO2 nanowire electrodes exhibited enhanced photoactivity in both the UV and the visible regions due to surface plasmon resonance of Au and showed the largest photocurrent generation of up to 710 nm. Pt/CdS/CGSe electrodes were developed as photocathode. With the role of p-n heterojunction, the photoelectrode showed high stability and evolved hydrogen continuously for more than 10 days. Further, in the Z-scheme system (Bi2S3/TNA as photoanode and Pt/SiPVC as photocathode at the same time), a self-bias (open-circuit voltage V oc = 0.766 V) was formed between two photoelectrodes, which could facilitate photogenerated charge transfers and enhance the photoelectrochemical performance, and which might provide new hints for PEC water splitting. Meanwhile, the existing problems and prospective solutions have also been reviewed.

The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/CrO x /TiO x /TiN structure for the first time. Transmission electron microscope image confirmed a via-hole size of 0.4 µm. A 3-nm-thick amorphous TiO x with 4-nm-thick polycrystalline CrO x layer was observed. A small 0.4-µm device shows reversible resistive switching at a current compliance of 300 µA as compared to other larger size devices (1-8 µm) owing to reduction of leakage current through the TiO x layer. Good device-to-device uniformity with a yield of >85 % has been clarified by weibull distribution owing to higher slope/shape factor. The switching mechanism is based on oxygen vacancy migration from the CrO x layer and filament formation/rupture in the TiO x layer. Long read pulse endurance of >105 cycles, good data retention of 6 h, and a program/erase speed of 1 µs pulse width have been obtained.

Cell labeling with magnetic iron oxide nanoparticles (IONPs) is increasingly a routine approach in the cell-based cancer treatment. However, cell labeling with magnetic IONPs and their leading effects on the biological properties of human lung carcinoma cells remain scarcely reported. Therefore, in the present study the magnetic γ-Fe2O3 nanoparticles (MNPs) were firstly synthesized and surface-modified with cationic poly-l-lysine (PLL) to construct the PLL-MNPs, which were then used to magnetically label human A549 lung cancer cells. Cell viability and proliferation were evaluated with propidium iodide/fluorescein diacetate double staining and standard 3-(4,5-dimethylthiazol-2-diphenyl-tetrazolium) bromide assay, and the cytoskeleton was immunocytochemically stained. The cell cycle of the PLL-MNP-labeled A549 lung cancer cells was analyzed using flow cytometry. Apoptotic cells were fluorescently analyzed with nuclear-specific staining after the PLL-MNP labeling. The results showed that the constructed PLL-MNPs efficiently magnetically labeled A549 lung cancer cells and that, at low concentrations, labeling did not affect cellular viability, proliferation capability, cell cycle, and apoptosis. Furthermore, the cytoskeleton in the treated cells was detected intact in comparison with the untreated counterparts. However, the results also showed that at high concentration (400 µg mL-1), the PLL-MNPs would slightly impair cell viability, proliferation, cell cycle, and apoptosis and disrupt the cytoskeleton in the treated A549 lung cancer cells. Therefore, the present results indicated that the PLL-MNPs at adequate concentrations can be efficiently used for labeling A549 lung cancer cells and could be considered as a feasible approach for magnetic targeted anti-cancer drug/gene delivery, targeted diagnosis, and therapy in lung cancer treatment.

We studied silicon, carbon, and SiC x nanostructures fabricated using liquid-phase electron-beam-induced deposition technology in transmission electron microscopy systems. Nanodots obtained from fixed electron beam irradiation followed a universal size versus beam dose trend, with precursor concentrations from pure SiCl4 to 0 % SiCl4 in CH2Cl2, and electron beam intensity ranges of two orders of magnitude, showing good controllability of the deposition. Secondary electrons contributed to the determination of the lateral sizes of the nanostructures, while the primary beam appeared to have an effect in reducing the vertical growth rate. These results can be used to generate donut-shaped nanostructures. Using a scanning electron beam, line structures with both branched and unbranched morphologies were also obtained. The liquid-phase electron-beam-induced deposition technology is shown to be an effective tool for advanced nanostructured material generation.

Direct synthesis of high-quality doped graphene on dielectric substrates without transfer is highly desired for simplified device processing in electronic applications. However, graphene synthesis directly on substrates suitable for device applications, though highly demanded, remains unattainable and challenging. Here, a simple and transfer-free synthesis of high-quality doped graphene on the dielectric substrate has been developed using a thin Cu layer as the top catalyst and polycyclic aromatic hydrocarbons as both carbon precursors and doping sources. N-doped and N, F-co-doped graphene have been achieved using TPB and F16CuPc as solid carbon sources, respectively. The growth conditions were systematically optimized and the as-grown doped graphene were well characterized. The growth strategy provides a controllable transfer-free route for high-quality doped graphene synthesis, which will facilitate the practical applications of graphene.

In this study, the impact of morphology of conductive agent and anode material (Fe3O4) on lithium storage properties was throughly investigated. Granular and belt-like Fe3O4 active materials were separately blended with two kinds of conductive agents (i.e., granular acetylene black and multi-walled carbon nanotube) as anodes in lithium-ion batteries (LIBs), respectively. It was found that the morphology of conductive agent is of utmost importance in determining LIBs storage properties. In contrast, not as the way we anticipated, the morphology of anode material merely plays a subordinate role in their electrochemical performances. Further, the morphology-matching principle of electrode materials was discussed so as to render their utilization more rational and effective in LIBs.

To have uniform nanoparticles individually dispersed on substrate before single-walled carbon nanotubes (SWNTs) growth at high temperature is the key for controlling the diameter of the SWNTs. In this letter, a facile approach to control the diameter and distribution of the SWNTs by improving the dispersion of the uniform Fe/Mo nanoparticles on silicon wafers with silica layer chemically modified by 1,1,1,3,3,3-hexamethyldisilazane under different conditions is reported. It is found that the dispersion of the catalyst nanoparticles on Si wafer surface can be improved greatly from hydrophilic to hydrophobic, and the diameter and distribution of the SWNTs depend strongly on the dispersion of the catalyst on the substrate surface. Well dispersion of the catalyst results in relatively smaller diameter and narrower distribution of the SWNTs due to the decrease of aggregation and enhancement of dispersion of the catalyst nanoparticles before growth. It is also found that the diameter of the superlong aligned SWNTs is smaller with more narrow distribution than that of random nanotubes.

In this work, three-dimensional hierarchical nickel-cobalt alloy coating for hydrogen evolution cathode was fabricated by electrodeposition processes. The coatings' morphology evolves from sea cucumber-like nanostructure to caterpillar-like one with the increase of cobalt content. A large amount of nanometric "steps," served as the active sites for hydrogen evolution reaction, were observed. According to Tafel polarization measurements, the exchange current density of the as-synthesized coating with hierarchical nanostructure was 21.9 times compared with that of flat nickel coating. In addition, the hierarchical coating also displayed good electrochemical stability from the galvanostatic test.

The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting. Hence, a method for controlling and removing the electrical charge needs to be developed. In this study, by using the electrode-deposited pipet tip (E-pipet tip), the charge-controlling system is newly developed and the electrical charge of a droplet is precisely controlled. The effect of electrolyte concentration and volume of the transferred solution to the electrical charge of a dispensed droplet is theoretically and experimentally investigated by using the equivalent capacitor model. Furthermore, a proof-of-concept example of the self-alignment and self-assembly of sequentially dispensed multiple droplets is demonstrated as one of the potential applications. Given that the electrical charge of the various aqueous droplets can be precisely and simply controlled, the fabricated E-pipet tip can be broadly utilized not only as a general charge-controlling platform of aqueous droplets but also as a powerful tool to explore fundamental scientific research regarding electrical charge of a droplet, such as the surface oscillation and evaporation of charged droplets.