显示样式:     当前期刊: Electrochimica Acta    加入关注    导出
我的关注
我的收藏
您暂时未登录!
登录
  • Boosting Pt oxygen reduction reaction activity and durability by carbon semi-coated titania nanorods for proton exchange membrane fuel cells
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-17
    P. Dhanasekaran, S. Vinod Selvaganesh, Avanish Shukla, N. Nagaraju, S.D. Bhat

    We report a simple, scalable approach to improve interfacial characteristics of carbon semi-coated titania nanorods-supported-Pt with superior peak power density as compared to Pt/C with thin metal loading of 150 μg cm−2. Thin layer of carbon coated titania nanorod is synthesized by hydrothermal method. Carbon coated titania nanorods boosts the Pt oxygen reduction reaction activity than carbon. The crystal structure, dispersion of platinum nanoparticles, surface morphology and oxidation state are studied by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy, respectively. Studies using conventional three electrode setup shows that Pt/CCT-30 retains 48% of initial electrochemical surface area even after 40,000 potential cycles between 0.6 and 1.2 V. The solid fuel cell mode accelerated stress durability studies show that thin layer of carbon coated titania nanorods-Pt (Pt/CCT 30) significantly enhances stability and preserves 75% of initial fuel cell performance even after 10,000 potential cycles between 1 and 1.5 V. In comparison, only 20% of performance is retained for Pt supported on carbon after 3000 cycles.

    更新日期:2018-01-17
  • Mesoporous perforated Co3O4 nanoparticles with a thin carbon layer for high performance Li-ion battery anodes
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-17
    Ji Sun Park, Dong Ok Shin, Churl Seung Lee, Young-Gi Lee, Ju Young Kim, Kwang Man Kim, Kwon Woo Shin

    A facile method for preparing mesoporous perforated Co3O4 nanoparticles with hollow channels and a thin carbon layer was newly designed and achieved with sacrificial carbon nanotube (CNT) templates. The threaded Co3O4 nanoparticles on the CNTs were fabricated through a hybridization process, and a subsequent calcination process produced mesoporous perforated Co3O4 nanoparticles. With a finely tuned calcination, CNTs were sacrificed to generate hollow channels in the Co3O4 nanoparticles and to provide a carbon source for the formation of a few nm-thick carbon layer on the surface of the Co3O4 nanoparticles simultaneously. The prepared mesoporous perforated Co3O4 nanoparticles with a robust electronic conductive layer enabled not only an enhanced electrochemical reactivity from the greatly increased contact area between the electrolyte and electrode but also a high electronic conductivity of the overall electrode so that excellent electrochemical performances (1115.1 mA h g−1 after 100 cycles; 595.9 mA h g−1 @ 5 C rate) were successfully achieved in the anode application of a lithium-ion battery.

    更新日期:2018-01-17
  • Cerium ion intercalated MnO2 nanospheres with high catalytic activity toward oxygen reduction reaction for aluminum-air batteries
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-17
    Shanshan Sun, Yejian Xue, Qin Wang, Heran Huang, He Miao, Zhaoping Liu

    Manganese oxide is one of the most extensively studied electrocatalysts for oxygen reduction reaction (ORR) due to its high abundance and environmental friendliness. In this work, cerium ion intercalated birnessite-type manganese oxide (δ-MnO2) dispersed on carbon (Ce single bond MnO2/C) with high-efficient oxygen reduction reaction(ORR) electrocatalytic ability in alkaline media is prepared via facile aqueous reactions for the first time. The as-prepared catalyst shows morphology like quasi special nanospheres intertwined by plenty of nanorods just like knitting wool balls. Compared with MnO2/C, the onset and half-wave potential of 4.8% Ce single bond MnO2/C shift positively 27 and 57 mV, respectively, and are close to those of Pt/C. The oxygen reduction reaction occurring on 4.8% Ce single bond MnO2/C undergoes a 4-electron transfer pathway with the HO2− yield lee than 2%, which is much lower than that produced on Pt/C. The Ce single bond MnO2/C catalyst also exhibits excellent long-term stability with current retention of 96.4% after aging for 40000 s. The aluminum-air battery applying 4.8% Ce single bond MnO2/C as cathode catalyst gives out the peak power density of 348.8 mW cm−2 in 4 M KOH aqueous solution. After more than 300-h discharging, the voltage degradation of 4.8% Ce single bond MnO2/C is only 2% per 100 h. In all, the excellent performance of the Ce-intercalated MnO2/C demonstrates its enormous potential as ORR catalyst in metal-air batteries.

    更新日期:2018-01-17
  • Combination of copolymer film (PPy-PPyCOOH) and magnetic nanoparticles as an electroactive and biocompatible platform for electrochemical purposes
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-17
    Edyta Matysiak-Brynda, Izabela Siekiera, Agata Królikowska, Mikolaj Donten, Anna M. Nowicka

    The process of obtaining the composite layer consisting of conductive copolymer, composed of unmodified pyrrole and pyrrole-3-carboxylic acid units (in various molar ratio) in combination with magnetic nanoparticles was investigated using voltammetry, scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy and surface enhanced Raman scattering (SERS) spectroscopy. The SERS and voltammetric data demonstrate that the use of molar concentration ratio of monomers 75 (Py) to 25 mM (Py-COOH) results in the conductive polymer layer with the best bioelectrochemical properties. The ferritin attached covalently to such composite demonstrated the highest electroactivity. Thus, mixed conductive copolymer film containing Py and Py-COOH units, combined with magnetic nanoparticles could be further useful in developing bioactive conductive platforms for specific biomedical purposes.

    更新日期:2018-01-17
  • Hollow spherical lithium-rich layered oxide cathode material with suppressed voltage fading
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-16
    Weixiang Ding, Xueyang Cui, Jie Lei, Xiaodong Lin, Shengliang Zhao, Qi-Hui Wu, Mingsen Zheng, Quanfeng Dong
    更新日期:2018-01-17
  • Anodic oxidation of anti-cancer drug Imatinib on different electrodes: Kinetics, transformation by-products and toxicity assessment
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-13
    Ozge Turkay, Sibel Barışçı, Ebru Ulusoy, Mine Gül Şeker, Anatoli Dimoglo
    更新日期:2018-01-15
  • Azulene-ethylenediaminetetraacetic acid: A versatile molecule for colorimetric and electrochemical sensors for metal ions
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-13
    George-Octavian Buica, Ioana-Georgiana Lazar, Liviu Birzan, Cecilia Lete, Mariana Prodana, Marius Enachescu, Victorita Tecuceanu, Andrei Bogdan Stoian, Eleonora-Mihaela Ungureanu

    A new synthesized molecular receptor, 2,2'-(ethane-1,2-diylbis((2-(azulen-2-ylamino)-2-oxoethyl)azanediyl))diacetic acid (L) has been used as building block for the development of new colorimetric and electrochemical sensors for metal ions complexation. The monomer L shows a high selectivity towards mercury ions among other cations, as highlighted by naked eye and UV–Vis spectra. The oxidative electropolymerization of L on glassy carbon electrodes lead to complexing polyL coated electrodes. They have been characterized by electrochemical techniques, their surface morphology and topography being evaluated by scanning electron microscopy and atomic force microscopy. These new modified electrodes show the ability to complex metal ions using chemical preconcentration-anodic stripping voltammetry technique.

    更新日期:2018-01-15
  • Fe-doped Co9S8 nanosheets on carbon fiber cloth as pH-universal freestanding electrocatalysts for efficient hydrogen evolution
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-13
    Kelong Ao, Dawei Li, Yixin Yao, Pengfei Lv, Yibing Cai, Qufu Wei
    更新日期:2018-01-15
  • Template synthesis of hierarchical mesoporous δ-MnO2 hollow microspheres as electrode material for high-performance symmetric supercapacitor
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-13
    Wei Xiao, Wenjie Zhou, Hong Yu, Yong Pu, Yanhua Zhang, Chengbo Hu

    The fabrication of graphene oxide (GO) thin layer encapsulated SiO2 microspheres (SiO2@GO) were accomplished by sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO2 microspheres. Then, hierarchical mesoporous δ-MnO2 hollow microspheres (δ-MnO2 HMS) were prepared by hydrothermal treatment of SiO2@GO microspheres in the presence of KMnO4, followed by removal of the SiO2 inner core in another hydrothermal reaction. The synthesized δ-MnO2 HMS was systematically characterized and found to exhibit remarkable supercapacitive performances in a three-electrode setup with the highest specific capacitance of 216.4 F g−1 at the current density of 0.5 A g−1, satisfactory rate capability and outstanding cyclic performance with the capacitance retention of 91.2% after consecutive charge/discharge at the current density of 5 A g−1 for over 3000 cycles. Such electrochemical behaviors of δ-MnO2 HMS electrode in a three-electrode system outperform those of a number of MnO2-based electrodes reported previously. Furthermore, a symmetric supercapacitor device of δ-MnO2 HMS//δ-MnO2 HMS was assembled. It released the maximum specific capacitance of 58.8 F g−1 at the current density of 0.25 A g−1, possessed excellent rate capability and favorable cycling stability with the capacitance retention up to 86.4% after cycling at the current density of 3 A g−1 for 3000 cycles, and offered the highest energy density of 8.2 W h kg−1 at a power density of 125 W kg−1, which was superior to that of many existing MnO2-based symmetric and asymmetric supercapacitors. The impressive electrochemical properties of δ-MnO2 HMS make it a promising candidate for constructing high-performance energy storage devices.

    更新日期:2018-01-15
  • 更新日期:2018-01-12
  • Electrodeposited molybdenum selenide sheets on nickel foam as a binder-free electrode for supercapacitor application
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Vimal Kumar Mariappan, Karthikeyan Krishnamoorthy, Parthiban Pazhamalai, Surjit Sahoo, Sang Jae Kim

    Two-dimensional nanostructured metal chalcogenides have fascinated significant consideration as electrode materials for energy storage application owing to their fascinating properties. In this work, we have grown two-dimensional MoSe2 sheets directly on the surface of nickel foam via facile one-step electrochemical deposition method and examined their use as a binder-free electrode for supercapacitor. The physicochemical characterizations such as X-ray diffraction, field emission scanning electron microscope, X-ray photoelectron spectrum, and Raman analysis confirmed the formation of MoSe2 sheets on Ni foam. The effect of deposition time (5 and 10 min) on the electrochemical properties of the MoSe2 sheets are examined in detail using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopic analyses, respectively. The cyclic voltammetry profiles confirmed that the charge-storage mechanism in MoSe2 sheets is due to the ion intercalation/de-intercalation kinetics. A specific capacity of 548 mAh g−1 was obtained for the MoSe2/Ni electrode from CV profile measured using a scan rate of 5 mV s−1. The MoSe2/Ni electrode delivered a high specific capacity of 325.92 mAh g−1 from charge-discharge analysis obtained at constant discharge current density of 4 mA cm−2 with good cyclic stability. The capacitive properties and the mechanism of charge-storage in the MoSe2/Ni electrode deposited at different time intervals were examined by the electrochemical impedance spectroscopy using Nyquist and Bode phase angle plot. The experimental results ensure that the MoSe2/Ni electrode might be used as the high-performance electrode for the next-generation energy storage devices.

    更新日期:2018-01-12
  • 更新日期:2018-01-12
  • Electrochemical reduction of porous vanadium trioxide precursors in molten fluoride salts
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Yapeng Kong, Jianshe Chen, Binchuan Li, Kuiren Liu, Qing Han

    The mechanism of the electrochemical reduction of vanadium trioxide (V2O3) towards the formation of metallic vanadium in molten NaF-AlF3 salts was investigated by cyclic voltammetry and constant potential electrolysis measurements. The porous V2O3 precursors were prepared from ammonium polyvanadate through coal gas reduction and sintering. The cathodic products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results indicated that the direct electrochemical reduction of V2O3 and aluminothermic reduction reaction both occurred during the reduction of V2O3, amongst which the latter plays a key role. A rapid electro-reduction of V2O3 was achieved through which the oxygen content of the metallic vanadium formed decreased to 0.216 mass% after 4 h of the electrolysis. The oxygen removed from the V2O3 cathode partly transported to the carbon anode in the form of Al single bond O single bond F complex ions, and partly existed in the form of aluminum oxide, which was then electrolyzed to realize the circulation of aluminum in the system.

    更新日期:2018-01-12
  • Polyethylene glycol assisted one-pot hydrothermal synthesis of NiWO4/WO3 heterojunction for direct Methanol fuel cells
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Mohamed Mokhtar Mohamed, M. Khairy, Salah Eid

    A novel hetero-junction anode composed of NiWO4/WO3, formed at various metal molar ratios (Ni/W) and fabricated hydrothermally via simple salt solution addition method using polyethylene glycol, was characterized using XRD, TEM-SAED, N2 sorptiometry, UV–Vis diffuse reflectance and FTIR spectrometry. Increasing NiO especially at the Ni/W ratio of 4 stimulates the develop of a tailored morphology (nanoplates/nanowires with crystallites size of 11 nm) with entailed mesoporous surface texturing values (SBET = 100.7 m2/g and Vp = .186 cm3/g) exceeding those exhibited at Ni/W ratio of 1 and 2 and rather shows a monomodal type of pores at 3.5 nm. The electrocatalytic performances of all nanocomposites toward methanol oxidation (0.6 M) were examined in comparison with pristine NiO and WO3 samples by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements. Strikingly, the NiWO4/WO3 electrode; synthesized at Ni/W ratio of 4, shows higher current density exceeding those of NiW(1:1) and NiW(2:1) by 3.4 and 2.6 fold, respectively. This pronounced electrocatalytic activity is mostly attributed to increasing the electrochemically active surface area of the former (16.9 cm2) and superior mesoporous nanostructures, which facilitate not only the diffusional electrochemical kinetics but also the long term cycle durability towards the CO poisoning species. This encountered stability was also due to the strong interaction between Ni and W to form small NiWO4 crystals of higher carrier density; as evaluated from the resistivity measurement, and to the hybridization with WO3 moieties of high electron transport properties, as confirmed by the EIS results.

    更新日期:2018-01-12
  • Facile activation of commercial Ni foil as robust cathode for advanced rechargeable Ni-Zn battery
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Xinyu Cheng, Lijun Zhou, Yongzhuang Lu, Wei Xu, Peng Zhang, Xihong Lu

    Developing stable and advanced aqueous Ni-Zn battery for meeting the power-source demands of wearable electronics are highly desirable. Herein, a facile and effective approach is proposed to activate commercial Ni foil to form highly active Ni(OH)2 layer as robust cathode for Ni//Zn battery. In comparison to the pristine Ni foil, the capacity of the activated Ni foils is greatly enhanced, yielding a remarkable discharge capacity of 0.57 mAh cm−3 with excellent rate and cycling performances. When directly using the activated Ni foils as cathode, a high-performance Ni//Zn battery with a maximum volumetric energy density of 2.89 mWh cm−3 is achieved. More improtantly, this as-fabricated Ni//Zn battery also owns outstanding cyclic stability, without any capacity decay after 5000 cycles under various current densities.

    更新日期:2018-01-12
  • Understanding the limits of rapid charging using instrumented commercial 18650 high-energy Li-ion cells
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Tazdin Amietszajew, Euan McTurk, Joe Fleming, Rohit Bhagat

    The charging rates of commercial high-energy Li-ion cells are limited by the manufacturer's specifications leading to lengthy charging times. However, these cells are typically capable of much faster charging, if one ensures that the thermal and electrode-specific voltage profiles do not exceed safety limits. Unfortunately, precise and in-situ measurements of these parameters have not been achieved to date without altering the operation of these cells. Here we present a method to assess the maximum current for commercial 18650s, using novel instrumentation methods enabling in operando measurements. We found the maximum charging current that could be safely applied to the evaluated high-energy cells is 6.7 times higher than the manufacturer-stated maximum. Subsequently a rapid-charging protocol was developed that leads to over five-fold reduction in charging times without compromising the safety limits of the cells. We anticipate our work to be a starting point for a more sophisticated understanding of commercial Li-ion cells through deployment of diverse in-situ sensor systems. This understanding will enable advances in battery materials science, thermal engineering and electrical engineering of battery technology. Furthermore, this work has the potential to help the design of energy storage systems for high performance applications such as motor racing and grid balancing.

    更新日期:2018-01-12
  • 更新日期:2018-01-12
  • Improved electrocatalytic oxygen evolution reaction properties using PVP modified direct growth Co-based metal oxides electrocatalysts on nickel foam
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Gracita M. Tomboc, Frank Ofori Agyemang, Hern Kim

    Polyvinyl pyrrolidone supported ZnCo2O4 and NiCo2O4 nanoparticles with 3D nanocactus and nanoflower-like morphology, respectively, directly grown on the surface of nickel foam through a one-step hydrothermal process followed by calcination treatment were used as improved electrocatalyst for oxygen evolution reaction. This study is continuation of our previous objective about the use of polyvinyl pyrrolidone as surface stabilizer and growth modifier during nanoparticles synthesis. The resulting products were analyzed by using X-ray diffraction (XRD), field emission scanning electron micrographs (FE-SEM) equipped with energy dispersive X-ray spectrometer (EDX), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). The calculated overpotential for ZnCo2O4 NPs is as low as 0.282 V while for NiCo2O4 NPs is 0.298 V. Additionally, ZnCo2O4 NPs had obtained a low Tafel slope of 79.90 mv dec−1 while 92.28 mV dec−1 Tafel slope for NiCo2O4 NPs. Lastly, the current density was almost retained during 24 h electrochemical running and obtained 97.74% and 96.18% efficiency, for ZnCo2O4 and NiCo2O4 NPs respectively.

    更新日期:2018-01-12
  • 更新日期:2018-01-12
  • 更新日期:2018-01-12
  • Hierarchical double-shelled poly(3,4-ethylenedioxythiophene) and MnO2 decorated Ni nanotube arrays for durable and enhanced energy storage in supercapacitors
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Xian-Xia Li, Xiao-Hua Deng, Qi-Jia Li, Sheng Huang, Kang Xiao, Zhao-Qing Liu, Yexiang Tong
    更新日期:2018-01-12
  • Determination of the critical micellar concentration of perfluorinated surfactants by cyclic voltammetry at liquid/liquid interfaces
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-12
    Benjamín Nahuel Viada, Ana Valeria Juárez, Erica Marcela Pachón Gómez, Mariana Adela Fernández, Lidia Mabel Yudi
    更新日期:2018-01-12
  • A high-performance hybrid Mg2+/Li+ battery based on hierarchical copper sulfide microflowers conversion cathode
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-11
    Ting Li, Aiqiong Qin, Hongtao Wang, Mengyi Wu, Yuyue Zhang, Yujie Zhang, Daohong Zhang, Fei Xu

    Hybrid Mg2+/Li+ batteries featuring dendrite-free Mg anode and Li-storage cathode are promising safe energy storage systems. However, improving the energy density remains a grand challenge due to the quite limited capacities of traditional Li-intercalation cathodes. To circumvent this limitation, a new type of conversion cathode for hybrid Mg2+/Li+ batteries, microflower-like Cu9S5, is reported herein. The Cu9S5 cathode is compatible with the dual-salt Mg2+/Li+ electrolyte, and delivers a high reversible capacity of 300 mAh g−1 at 50 mA g−1 via electrochemical conversion reaction, with 94% capacity retention over 100 cycles in hybrid Mg2+/Li+ batteries. The electrode also shows an outstanding rate capability providing 155 mAh g−1 at 1000 mA g−1 and a superior long-term cycleability over 1000 cycles. This excellent performance is attributed to the hierarchical architecture of Cu9S5 which facilitates the reversible conversion reactions and stabilizes the electrode structure during discharge/charge process. This work provides new insight for the nanostructure design of stable conversion electrodes, and opens a new avenue for building safe and high-performance hybrid Mg2+/Li+ batteries for practical applications.

    更新日期:2018-01-12
  • Scalable synthesis of Mo2C/CNT networks as highly efficient and stable electrocatalyst for hydrogen evolution reaction
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-11
    Yang Hu, Deng-gao Guan, Bo Yu, Wenqiang Hou, Binjie Zheng, Wanli Zhang, Yuanfu Chen

    The efficient generation of clean hydrogen energy through the water splitting has attracted much more attention. However, lacking of low-cost and highly efficient electrocatalysts is still a major obstacle for hydrogen generation via hydrogen evolution reaction (HER). Herein, for the first time, we present a facile, low-cost and scalable synthesis of highly efficient and stable Mo2C/CNT hybrid via spray drying followed by carbonization process (Mo2C/CNT-SC). The optimized Mo2C/CNT-SC hybrid delivers superior HER performance with a low Tafel slop of 53.6 mV dec−1, and an extremely low onset overpotential of ∼20 mV (vs RHE) @ 1 mA cm−2, which is much lower than those of most reported electrocatalysts and comparable to that of Pt-based electrocatalysts. The Mo2C/CNT-SC hybrid also shows excellent stability even after 1000 cycles. The superior HER performance of Mo2C/CNT-SC can be attributed to its unique conductive and porous structure constructed by ultrasmall Mo2C nanoparticles homogenously embedded in CNT networks, which can not only provide sufficient HER active sites, but also guarantee full contact between the Mo2C nanoparticles and CNT networks. The principles demonstrated in our work can be extended to scalable synthesis of other non-noble metal electrocatalysts with excellent HER performance.

    更新日期:2018-01-12
  • Performance of double perovskite symmetrical electrode materials Sr2TiFe1–xMoxO6–δ (x = 0.1, 0.2) for solid oxide fuel cells
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-11
    Bingbing Niu, Fangjun Jin, Leilei Zhang, Pengfei Shen, Tianmin He
    更新日期:2018-01-12
  • In-situ synthesis of carbon@Ti4O7 non-woven fabric as a multi-functional interlayer for excellent lithium-sulfur battery
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-11
    Hao Tang, Shanshan Yao, Sikang Xue, Mingquan Liu, Lili Chen, Maoxiang Jing, Xiangqian Shen, Tianbao Li, Kesong Xiao, Shibiao Qin
    更新日期:2018-01-11
  • 更新日期:2018-01-11
  • Enhanced electrochromism in short wavelengths for NiO:(Li, Mg) films in full inorganic device ITO/NiO:(Li, Mg)/Ta2O5/WO3/ITO
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Dongmei Dong, Wenwen Wang, Antoine Barnabé, Lionel Presmanes, Aline Rougier, Guobo Dong, Fan Zhang, Hang Yu, Yingchun He, Xungang Diao

    Great interest has been drawn to the electrochromism demonstrated by inorganic materials, leading to various applications including smart windows and displays. NiO, as a cheap material, shows anodic electrochromism and is highly suitable for device applications in conjunction with WO3, but its strong optical absorbance has been largely overlooked. Herein, improved electrochromic properties in particular in short wavelengths was achieved by co-doping of Mg and Li in NiO:(Li, Mg) thin films grown using RF sputtering. Secondary Ion Mass Spectroscopy technique in combination with X-ray Photoelectron Spectroscopy characterization provides direct evidence of the introduction of Mg as well as Li in the film. Whatever the Li and Mg content, X-Ray Diffraction and Raman spectroscopy studies only bring out the NiO face-centered cubic rock salt structure. Electrochemical cycling shows pronounced anodic electrochromism for NiO:(Li, Mg) thin films. Inorganic all-solid-state monolithic multilayered devices are traditionally composed of a pair of electrodes with NiO and WO3 separated by Li containing electrolyte such as LiTaO3 or LiNbO3 sputtered from expensive but low efficient ceramic targets. Based on optimal NiO:(Li, Mg) films, large switchable electrochromism both in visible (∼58%) and ultraviolet band (∼50%) is reconciled in electrochromic device Glass/ITO/NiO:(Li, Mg)/Ta2O5/WO3/ITO. The co-doping of NiO with Mg and Li is capable of simultaneously widening the gap and avoiding the use of Li containing electrolyte, through NiO pre-lithiation. We believe the new, low-cost approach would provide references with respect to practical applications desired for their successful commercial mass production.

    更新日期:2018-01-11
  • Model-supported characterization of a PEM water electrolysis cell for the effect of compression
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Steffen Henrik Frensch, Anders Christian Olesen, Samuel Simon Araya, Søren Knudsen Kær

    This paper investigates the influence of the cell compression of a PEM water electrolysis cell. A small single cell is therefore electrochemically analyzed by means of polarization behavior and impedance spectroscopy throughout a range of currents (0.01 A cm−2 to 2.0 A cm−2) at two temperatures (°60C60°C and °80C80°C) and eight compressions (0.77 MPa–3.45 MPa). Additionally, a computational model is utilized to support the analysis. The main findings are that cell compression has a positive effect on overall cell performance due to decreased contact resistances, but is subject to optimization. In this case, no signs of severe mass transport problems due to crushed transport layers are visible in either polarization curves or impedance plots, even at high currents. However, a Tafel plot analysis revealed more than one slope throughout the current range. The change in the Tafel slope is therefore discussed and connected to the electrochemical reaction or an ohmic contribution from a non-electrode component.

    更新日期:2018-01-11
  • Hybrid of Fe4[Fe(CN)6]3 nanocubes and MoS2 nanosheets on nitrogen-doped graphene realizing improved electrochemical hydrogen production
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Xiao Zhang, Yanhua Wu, Yanfang Sun, Peng Ding, Qingyun Liu, Lin Tang, Jinxue Guo
    更新日期:2018-01-11
  • Electrochemical sensing of hydrogen peroxide using Pd@Ag bimetallic nanoparticles decorated functionalized reduced graphene oxide
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Muhammet Guler, Vedat Turkoglu, Ahmet Bulut, Mehmet Zahmakiran
    更新日期:2018-01-11
  • Modifying the ORR route by the addition of lithium and potassium salts in Na-O2 batteries
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Imanol Landa-Medrano, Idoia Ruiz de Larramendi, Teófilo Rojo
    更新日期:2018-01-11
  • Quantitative Raman spectroelectrochemistry using silver screen-printed electrodes
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Daniel Martín-Yerga, Alejandro Pérez-Junquera, María Begoña González-García, Juan V. Perales-Rondon, Aranzazu Heras, Alvaro Colina, David Hernández-Santos, Pablo Fanjul-Bolado

    Surface enhanced Raman scattering (SERS) is a powerful technique based on the intensification of the Raman signal because of the interaction of a molecule with a nanostructured metal surface. Electrochemically roughened silver has been widely used as SERS substrate in the qualitative detection of analytes at the ultra-trace level. However, its potential for quantitative analysis has not been widely exploited yet. In this work, the combination of time-resolved Raman spectroelectrochemistry with silver screen-printed electrodes (SPE) is proposed as a novel methodology for the preparation of SERS substrates. The in situ activation of a SERS substrate is performed simultaneously with the analytical detection of a probe molecule, controlling the process related to the preparation of the substrate and performing the analytical measurement in real time. The results show the good performance of silver SPE as electrochemically-induced surface-enhanced Raman scattering substrates. Raman spectra were recorded at fairly low integration times (250 ms), obtaining useful spectroelectrochemical information of the processes occurring at the SPE surface with excellent time-resolution. By recording the microscopic surface images at different times during the experiment, we correlated the different data obtained: structural, optical and electrochemical. Finally, the in situ activation process was used to obtain a suitable in situ SERS signal for ferricyanide and tris(bipyridine)ruthenium (II) quantification. The detection of the analytes at concentrations of a few tens of nM was possible with a low integration time (2 s) and good precision, demonstrating the exceptional performance of the Raman spectroelectrochemical method and the possibility to use cost-effective screen-printed electrodes for applications where a high sensitivity is needed.

    更新日期:2018-01-11
  • 更新日期:2018-01-11
  • Cobalt-doped molybdenum disulfide in-situ grown on graphite paper with excellent electrocatalytic activity for triiodide evolution
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Fang Zheng, Niu Huang, Rongcheng Peng, Yuyue Ding, Guowang Li, Zhifen Xia, Panpan Sun, Xiaohua Sun, Jiguo Geng

    Molybdenum disulfide (MoS2) is considered as a promising candidate to Pt-based catalysts. Literatures report the active centers of MoS2 locate at its edges, while the perfect in-plane domains are not active. In this study, a simple Co<img border="0" alt="single bond" src="https://cdn.els-cdn.com/sd/entities/sbnd">Mo<img border="0" alt="single bond" src="https://cdn.els-cdn.com/sd/entities/sbnd">S precursor decomposition approach is used to synthesize Co-doped MoS2 in-situ grown graphite paper (GP) substrate. Electrochemical analyses reveal the Co-doped MoS2 possesses excellent electrocatalytic activity comparable to Pt. Density functional theory (DFT) calculations indicate the inert in-plane S atoms neighboring the doped Co atoms become active towards triiodide reduction, as revealed by the adsorption energies (Ead) of iodine atom decreasing from 0.36 eV to −0.52 eV, identical with value obtained from Pt (−0.52 eV). Due to increased active sites, highly conductive of GP, and excellent electrical connection between Co-doped MoS2 and GP substrate, the dye-sensitized solar cell fabricated using Co-doped MoS2/GP as counter electrode (CE) shows higher photoelectric conversion efficiency (7.26%) than those based on MoS2/GP CE (6.57%) and platinized F-doped tin oxide (Pt/FTO) electrode (6.87%).

    更新日期:2018-01-11
  • Observation of the intercalation of dimethyl sulfoxide-solvated lithium ion into graphite and decomposition of the ternary graphite intercalation compound using in situ Raman spectroscopy
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Shohei Maruyama, Tomokazu Fukutsuka, Kohei Miyazaki, Takeshi Abe

    Dimethyl sulfoxide (DMSO) is electrochemically co-intercalated with lithium ions into graphite to form a stable ternary graphite-intercalation-compound (GIC), Li-DMSO-GIC. To elucidate the details of the co-intercalation behavior, in situ Raman spectroscopy was performed to observe the structural variations in graphite during the potential scan. During the scan from 2.44 to 1.00 V, DMSO was co-intercalated with lithium ions into graphite, exhibiting a staged structure. The stage number decreased from 4 to 1. During the scan from 1.00 to 2.44 V, the deintercalation of DMSO-solvated lithium ions was observed. After experienced a potential cycle between 2.4 and 0 V, the graphite exhibited significant changes that are ascribed to the exfoliation of graphite, implying that the destruction of the graphite composite electrode is likely to be caused by the decomposition of DMSO within the graphite layer.

    更新日期:2018-01-11
  • Effects of the LiPO2F2 additive on unwanted lithium plating in lithium-ion cells
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Q.Q. Liu, Lin Ma, C.Y. Du, J.R. Dahn

    The effect of the additive lithium difluorophosphate (LiPO2F2) on unwanted lithium plating in lithium-ion cells was studied in this work. Li[Ni1/3Mn1/3Co1/3]O2/graphite pouch cells were cycled at high charge rates where unwanted lithium plating was identified as the major aging mechanism. LiPO2F2 used as a single electrolyte additive reduced cell impedance growth during cycling even at high charge rate (i.e. 2C) at 20 °C. Electrochemical impedance spectroscopy (EIS) measurements on symmetric cells showed that LiPO2F2 reduced the growth of both positive and negative electrode impedances during cycling. The effects of LiPO2F2 depend strongly on the presence of other additives. When LiPO2F2 was combined with 2% propene sultone (PES) + 1% ethylene sulfate (DTD) + 1% tris(-trimethyl-silyl)-phosphite (TTSPi) (called PES211), the cell impedance increased which led to unwanted lithium plating. When 1% LiPO2F2 was used in combination with ethylene sulfate (DTD) or fluoroethylene carbonate (FEC) the impedance of the cells grew more slowly with cycling than with DTD or FEC added alone. Normally, but not always, additions of LiPO2F2 reduce cell impedance. The choice of additives to use along with LiPO2F2 must be made wisely to ensure synergistic action.

    更新日期:2018-01-10
  • Progress in nanostructured (Fe or Co)/N/C non-noble metal electrocatalysts for fuel cell oxygen reduction reaction
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-10
    Lei Zhang, David P. Wilkinson, Yuyu Liu, Jiujun Zhang

    The high cost and limited supply of platinum for Pt-based catalysts in proton exchange membrane fuel cells (PEMFCs) have driven intensive research into the use of non-noble metal catalysts in recent years. As the most promising non-noble metal catalysts for PEMFC oxygen reduction reactions (ORR), metal/N/C class of catalysts has been extensively explored. Earlier efforts (1964–2004) were mainly focused on the exploration of various synthesis routes and the investigation of active site mechanisms. During recent years (2005–2010), great progress in the development of these types of non-noble metal catalysts in real PEMFC environments has been achieved both in terms of catalytic activity and stability. From 2011 to present, several new synthetic approaches have been explored to produce highly dense catalytically active sites decorated within micropores using rationally designed zeolite imidazolate frameworks (ZIFs) and porous organic polymers (POPs). Currently, the most active non-noble metal catalysts are derived using this method and are able to deliver a kinetic volumetric current density of 450 A/cm3 at 0.8 V under fuel cell operating conditions. These results are superior to the US DOE 2020 target of 300 A/cm3. In terms of fuel cell maximum power density, the best non-noble metal catalysts for cathodes can achieve results as high as 0.98 W/cm2 and 0.41 W/cm2 with feeds of pure O2 and air respectively. In terms of stability, some non-noble metal catalysts have remained stable for over 1000 h with only minor degradation under PEMFC conditions. Nonetheless, activity and stability still remain major challenges for non-noble metal catalysts when compared to Pt-based ones in PEMFCs. Improvements in the structure of both catalysts and catalyst layers are urgently needed to realize the activity targets established for automobile fuel cell applications as well as the US DOE Hydrogen and Fuel Cell (H&FC) program. In the long term and the sustainable commercialization of fuel cells, replacing Pt-based catalysts with non-noble metal catalysts is, in the present authors' opinion, the most sustainable solution. Therefore, further intensive research into fundamental studies is critical to uncovering the workings of active site mechanisms. Once controllable design and synthesize of non-noble metal catalysts with high active site densities and utilization can be achieved, the goal of cost-effective, non-noble metal catalysts in automobile fuel cells can become reality.

    更新日期:2018-01-10
  • Removal of Procion Red MX-5B dye from wastewater by conductive-diamond electrochemical oxidation
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-09
    Salvador Cotillas, Javier Llanos, Pablo Cañizares, Davide Clematis, Giacomo Cerisola, Manuel A. Rodrigo, Marco Panizza
    更新日期:2018-01-10
  • 更新日期:2018-01-10
  • “Water-in-ionic liquid” solutions towards wide electrochemical stability windows for aqueous rechargeable batteries
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-09
    Yonglai Zhang, Ruijie Ye, Dirk Henkensmeier, Rolf Hempelmann, Ruiyong Chen

    Several hydrophilic ionic liquids dissolved in water with different molalities are studied as “water-in-ionic liquid” supporting electrolytes. They exhibit wide electrochemical stability window from 3 to 4.4 V, high ionic conductivities and good flowability, making them promising supporting electrolytes for aqueous high-voltage rechargeable batteries. In such supporting electrolytes, enhanced redox activities of lithium insertion/extraction in anodic TiO2 film at low negative potential and Fe3+/Fe2+ couple at moderate positive potential were observed. Cyclability of an aqueous TiO2/Fe2+ hybrid battery is demonstrated with a voltage of 1.7 V.

    更新日期:2018-01-10
  • Corrosion mechanism in PVD deposited nano-scale titanium nitride thin film with intercalated titanium for protecting the surface of silicon
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-09
    Ali Usman Chaudhry, Bilal Mansoor, Tarang Mungole, Georges Ayoub, David P. Field

    In this work, thin film systems consisting of: (i) monolithic titanium nitride, (ii) monolithic titanium, and, (iii) titanium nitride with intercalated titanium, were fabricated on <100> P-type Si wafers by magnetron sputtering. The thin films were characterized using electron microscopy, glancing angle x-ray diffraction and nanoindentation. Their impedance response was studied via open circuit potential and electrochemical impedance spectroscopy in a sodium chloride aqueous solution. The influence of intercalated Ti thickness on impedance behavior was investigated in detail. Scanning electron microscopy analysis confirmed the columnar structure of TiN and aggregated structure of Ti thin films. Further microstructural analysis confirmed the presence of nano-porosities in thin films which explained their low modulus and hardness. Analysis of impedance data with equivalent circuit models indicated that incorporation of titanium as intercalated layer between titanium nitride and silicon surface, greatly altered the impedance characteristics of Si. Higher impedance values of thin films were achieved for bi-layer configuration at a much smaller total thickness as compared to monolithic counterparts. The increase in impedance was attributed to the presence of less defective and compact intercalated Ti layer that effectively interrupted the corrosive ions pathways.

    更新日期:2018-01-10
  • 更新日期:2018-01-10
  • Stabilizing the electrodeposit-electrolyte interphase in soluble lead flow batteries with ethanoate additive
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-09
    Yan-Ting Lin, Hao-Lun Tan, Chun-Yen Lee, Hsun-Yi Chen
    更新日期:2018-01-09
  • Metal-organic-framework derived carbon polyhedron and carbon nanotube hybrids as electrode for electrochemical supercapacitor and capacitive deionization
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-09
    Tie Gao, Feng Zhou, Wei Ma, Haibo Li

    In this work, carbon polyhedron and carbon nanotube hybrids (HCN) have been synthesized by employing ZIF-67 as precursor for electrochemical supercapacitor and capacitive deionization (CDI). Basically, uniform polyhedral nanocrystals of ZIF-67 were firstly fabricated, and then they were directly subjected to chemical vapor deposition for growing carbon nanotubes. It is found that the as-fabricated HCN electrode exhibits remarkable electrochemical performance, i.e. the highest capacitance of 343 F g−1 at the scan rate of 10 mV s−1 and excellent rate capability. This is due to that HCN can provide rich space and short ion diffusion path. Moreover, the HCN electrodes shows superior CDI performance, i.e. the electrosorption capacity reached as high as 7.08 mg g−1 and the adsorption rate of 0.03958 mg g−1·min−1.

    更新日期:2018-01-09
  • Identification of the best chemical equivalent ratio to produce emeraldine salt exhibiting better pseudo capacitance
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-09
    S. Venkatesh, K. Vishista

    This work details the effect of varying the ratio of concentrations of oxidant-to-monomer, in the process of synthesizing Polyaniline (PANI) in emeraldine salt (oxidation state) form for pseudo capacitor application. The formation of emeraldine salt is confirmed by analytical characterizations such as Fourier Transform Infrared spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Raman analysis techniques. The UV/Vis spectroscopic (UV) technique was employed to elucidate the optical band gap of variants. Both DC and AC measurements have shown a maximum total conductivity of 1.296 × 103 S cm−1. The cyclic voltammetry (CV) of variants exhibit reversible redox reactions due to back and forth transitions between emeraldine and pernigraniline oxidation states and high diffusion of ions in the fabricated polyaniline thin films. The electrochemical impedance spectroscopy has shown their low solution resistances and charge transfer resistances behaving like a near ideal capacitor and the specific capacitances of CER variants have been calculated by performing constant current discharge cell test showing a maximum specific capacitance of 30.2 Fg−1. The variants also exhibit better coulombic efficiencies.

    更新日期:2018-01-09
  • Electro-polymerisation and characterisation of PEDOT in Lewis basic, neutral and acidic EMImCl-AlCl3 ionic liquid
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-09
    T. Schoetz, C. Ponce de Leon, A. Bund, M. Ueda

    This work studied the electro-polymerisation of 3,4-ethylenedioxythiophene (EDOT) and its electrochemical behavior in Lewis acidic, neutral and basic chloroaluminate ionic liquid 1-ethyl-3-methylimidazolium chloride aluminum chloride (EMImCl-AlCl3) by cyclic voltammetry. It was found that the electro-polymerisation on vitreous carbon only occurs in Lewis neutral EMImCl-AlCl3 as a dark blue-violet film whereas the electro-polymerisation in a Lewis acidic or basic compositions is not possible due to the interactions between the conductive polymer and the ionic liquid as well as the potential stability limits of the electrolyte. PEDOT films synthesised in Lewis neutral ionic liquid were tested in monomer-free Lewis acidic, basic and neutral EMImCl-AlCl3 and show different doping and de-doping behavior for chloride ionic species. The PEDOT films in a Lewis neutral composition showed higher doping levels due to the higher potential stability window, up to 2.6 V vs. Al|Al(III) than in a Lewis acidic and basic solutions. Furthermore, it was shown that the doping and de-doping levels are predefined during the electro-polymerisation of PEDOT. The anion doping and de-doping reaction reached 97% reversibility in the neutral composition, which suggests that PEDOT is a suitable electrode material to store charged species in this media and could be used in rechargeable energy storage devices.

    更新日期:2018-01-09
  • Fabrication and characterization of porous, conductive, monolithic Ti4O7 electrodes
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-08
    Sasmita Nayak, Brian P. Chaplin
    更新日期:2018-01-08
  • Coupling plasmonic nanoparticles with TiO2 nanotube photonic crystals for enhanced dye-sensitized solar cells performance
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-08
    Min Guo, Jia Chen, Jun Zhang, Haijun Su, Lin Liu, Nianqing Fu, Keyu Xie
    更新日期:2018-01-08
  • 更新日期:2018-01-08
  • Improving salt-to-solvent ratio to enable high-voltage electrolyte stability for advanced Li-ion batteries
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-08
    O.A. Drozhzhin, V.A. Shevchenko, M.V. Zakharkin, P.I. Gamzyukov, L.V. Yashina, A.M. Abakumov, K.J. Stevenson, E.V. Antipov
    更新日期:2018-01-08
  • Designing high-power graphite-based dual-ion batteries
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-08
    C.Y. Chan, Pui-Kit Lee, Z. Xu, Denis Y.W. Yu

    Dual-ion battery with the use of both cations and anions as means of energy storage promises high power, as the ions do not have to travel from one electrode to another during charge and discharge. Though, actual rate performance of an electrode is highly dependent on material, electrode configuration and electrolyte. Here, we have identified the key parameters governing the rate performance of PF6− intercalation into graphite. Capacity is increased by increasing the surface area of the graphite material. Electrical conductivity and stability are enhanced with carbon addition in the electrode with reduced cut-off voltage. Operating voltage is reduced by increasing the salt concentration, and ionic conductivity is improved with the use of carboxymethyl cellulose as binder. Optimized graphite electrode delivers a capacity of about 90 mAh g−1 at 10 mA g−1, and 90% of it can still be accessible at a rate of 500 mA g−1, with excellent cycle stability for at least 200 cycles. The dual-ion battery is demonstrated to give power density superior to that of lithium-ion battery, and energy density superior to that of supercapacitor.

    更新日期:2018-01-08
  • Catalytic effect of pyrite on the leaching of arsenopyrite in sulfuric acid and acid culture medium
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-08
    Sha Deng, Guohua Gu, Guoshuai He, Lijuan Li

    In this study, the influence of pyrite on the leaching of arsenopyrite in sulfuric acid and iron-free 9K medium was investigated by leaching experiments and electrochemical analysis. During acid leaching, the addition of pyrite resulted in the further oxidation of arsenopyrite, for the reason that the galvanic interaction made the pH increase and redox potential decrease, and then the formation of arsenate precipitates with high crystallinity was depressed. While leaching in iron-free 9K medium, the buffer action keeping the pH stable promoted arsenopyrite dissolution as compared with acid leaching. And the addition of pyrite facilitated the arsenic extraction, but increasing the amount of pyrite added had no distinct impact on the further leaching of arsenopyrite. Electrochemical studies revealed that the presence of pyrite increased the conductivity of electrodes and electrolytes, verifying the catalytic effect of galvanic interaction on arsenopyrite leaching. Additionally, in the sulfuric acid electrolyte, the addition of pyrite also decreased the thickness of passivation layer on the arsenopyrite surface, confirming that the formation of ferric arsenate precipitates with high crystallinity was inhibited in the presence of pyrite. Therefore, the pyrite-promoted arsenopyrite oxidation in sulfuric acid was due to the galvanic effect and the control of pH and redox potential, whereas that in culture medium was only associated with the galvanic effect. Moreover, the electrochemical measurements also showed that the oxidation of elemental sulfur was the rate controlling step for arsenopyrite dissolution.

    更新日期:2018-01-08
  • 更新日期:2018-01-08
  • Thermal influence on the electrochemical behavior of a supercapacitor containing an ionic liquid electrolyte
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-06
    Mazharul Haque, Qi Li, Anderson D. Smith, Volodymyr Kuzmenko, Elof Köhler, Per Lundgren, Peter Enoksson

    Emerging demands on heat-durable electronics have accelerated the need for high temperature supercapacitors as well as for understanding the influence of elevated temperatures on the capacitive behavior. In this work, we present a comprehensive study of the thermal influence on a supercapacitor containing 1-ethyl-3-methylimidazolium acetate (EMIM Ac) electrolyte and activated carbon (AC) electrodes. The performance variation as a function of temperature in a range from 21 °C to 150 °C reveals that a high specific capacitance of 142 F g−1 can be achieved at 150 °C at a current density of 2 A g−1 with a rate capability of 87% at 15 A g−1 (relative to 2 A g−1). At 150 °C, equivalent series resistance (ESR) is only 0.37 Ω cm2, which is a result of improved ionic conductivity of the electrolyte at elevated temperature. The ESR value of 2.5 Ω cm2 at room temperature reflects a good compatibility between EMIM Ac and AC. In addition, a capacitance retention of more than 95% (in the end of 1000 cycles) is maintained up to120 °C followed by 85% at 150 °C. These results confirm EMIM Ac as a suitable candidate for carbon-based high temperature supercapacitors, and the observations regarding the thermal influence on performance metrics e.g. usable operation voltage could be applicable to other energy storage devices.

    更新日期:2018-01-06
  • 更新日期:2018-01-06
  • Synthesis and characterization of porous carbon derived from activated banana peels with hierarchical porosity for improved electrochemical performance
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-05
    O. Fasakin, J.K. Dangbegnon, D.Y. Momodu, M.J. Madito, K.O. Oyedotun, M.A. Eleruja, N. Manyala
    更新日期:2018-01-06
  • 更新日期:2018-01-06
  • Nanosized graphene sheets induced high electrochemical activity in pure carbon film
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-05
    Liangliang Huang, Yuanyuan Cao, Dongfeng Diao

    We found that nanosized graphene sheets induced high electrochemical activity in pure carbon films, which prepared by electron cyclotron resonance (ECR) plasma sputtering under low-energy electron irradiation condition. The electrochemical properties were studied by electrochemical impedance spectroscopy and cyclic voltammetry. The graphene sheets embedded carbon (GSEC) films showed a wide potential window over 3.2 V. The charge transfer resistance and the oxidation-reduction peak separation (ΔEP) of the GSEC films are lower than amorphous carbon films in several redox systems (Fe(CN)64−/3-, Ru(NH3)62+/3+, dopamine and ascorbic acid), especially in the inner-sphere system, the ΔEP is only half of amorphous carbon films. The high electrochemical activity of GSEC films originated from the nanosized graphene sheets, which offered faster electron transfer path and more reaction active sites. Our results indicate the GSEC films have great potential to be an electrochemical biosensor in detecting biomolecules with high oxidation potential.

    更新日期:2018-01-06
  • In situ growth of zinc oxide nanoribbons within the interstices of a zinc stannate nanoplates network on compacted woven metal wires and their enhanced solar energy application
    Electrochim. Acta (IF 4.798) Pub Date : 2018-01-05
    Zhengdao Li, Dongqin Bi, Yiyang Zhao, Ruiheng Liu, Jinhua Ye, Yong Zhou

    A novel hybrid film is designed and prepared by in situ growth of ZnO nanoribbons in the interstices of Zn2SnO4 nanoplates network on the compacted woven metal wires through a simple process. The ZnO nanoribbons present in the ZnO/Zn2SnO4 composite film can enhance light harvesting, accelerate electron transport and induce a negative shift in the flat-band potential. Benefiting from its advantageous structure and composition, the ZnO/Zn2SnO4 film can be applied in many fields. For the flexible dye-sensitized solar cells (FDSSCs) employing optimized ZnO/Zn2SnO4 as a photoanode, the conversion efficiency reaches 2.41% corresponding to ∼36.2% improvement relative to the Zn2SnO4 nanoplates-based FDSSCs. Moreover, ZnO/Zn2SnO4-based FDSSC shows relatively good mechanical stability and long-term stability, retaining 95.1% and 93.3% of its initial efficiency after ten consecutive bending tests and after 15 days under sunlight, respectively; Additionally, the immobilized ZnO/Zn2SnO4 on the metal wires exhibits 96.8% photocatalytic degradation efficiency against an organic dye under UV light, and the photocatalytic performance can be restored almost completely by a simple chemical treatment. More importantly, the in situ growth technique demonstrated in this work can be adopted to fabricate other composite oxides on flexible substrates with high curvature surfaces for additional practical applications in flexible devices.

    更新日期:2018-01-05
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.
化学 • 材料 期刊列表