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Electrochemical codeposition of truncated octahedral cuprous oxide/reduced graphene oxide composite towards efficient oxygen reduction reaction

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Electrochemical codeposition of truncated octahedral cuprous...

MODELING OF THE PROCESS OF COMPOSITE ELECTRODEPOSITION

中国化学会第九届全国无机化学学术会议

作者： Xiaofeng Zhang Xiaoying Wang Lijuan Le Shen Lin College of Chem. & Chem. Engin. Fujian Normal Univ.

Due to the high catalytic activity for oxygen reduction reaction(ORR), platinum has long been regarded as one of the best cathode catalysts for fuel cells. However, the high cost and poor tolerance to fuel crossover and CO poisoning have greatly limited its commercialization. Therefore, numerous efforts have been devoted to exploring new ORR catalysts with less or no usage of Pt [1]. It has been reported that Cu2O can be used as a potential electrocatalyst for ORR and it shows structure-dependent electrocatalytic activity toward ORR in alkaline electrolyte [2]. In this work, truncated octahedral Cu2O/RGO(reduced graphene oxide) composite(Fig. a) was successfully prepared by a one-step electrochemical galvanostatic codeposition approach. The TEM image(Fig. b) reveals that the size of truncated octahedral Cu2O disperses on the RGO sheets is about 500000 nm. The electrocatalytic ORR performance of as-synthesized Cu2O/RGO composite was also studied. Fig. c shows a series of ORR polarization curves recorded at Cu2O/RGO in 0.1 M KOH solution at different rotation rates(from 225 to 3000 rpm). There is only one stage with defined current density and the limiting current density increases with increasing rotation rate. Such ORR polarization curves feature reveals that the ORR on Cu2O/RGO can proceed via the most efficient four-electron process. The numbers of electrons transferred can be calculated to be 3.9(≈4) for ORR on Cu2O/RGO from- 0.40 V to-0.80 V, thereby indicating that the ORR is dominated by a near four-electron(4e) process and O2 is reduced to OH-. Therefore, this study could provide guidance in the further development of easily prepared, scalable, and low-cost catalysts based on other metal oxides.

关键词： cuprous oxide reduced graphene oxide codeposition oxygen reduction reaction.

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中国有色金属学会会刊：英文版 1996年第4期6卷 26-30页

作者： Xie Yan Hu Wenbin Luo Shoufu Gu Mingyuan(State Key Laboratory of MMCS,Shanghai Jiao Tong University,Shanghai 200030) SHANGHAI JIAO TONG UNIV STATE KEY LAB MMCSSHANGHAI 200030PEOPLES R CHINA

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关键词： composite eletrodeposition mathematical model of codeposition process

Electrodeposition of La-Ni Alloy Powders in Dimethylsulfoxide (DMSO)

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Journal of Rare Earths 2005年第S1期23卷 125-127页

作者：郭琳尹伟 Department of Chemistry Guangdong Education Institute Guangzhou 510303 China

The brown metallic luster La-Ni alloy powders were prepared by potentiostatic electrolysis technique in dimethylsulfoxide solution at room temperature. The atomic rate of La and Ni in alloy powders are 11∶1 and 10∶1. The size of metal grains is about 0.1 to 100 μm. It shows that the micrometer powders of rare earth alloys can be obtained by controlling electrodeposition conditions. The peak potentials of -2.81 and 1.75 V are attributed to reduction of La 3+ and Ni 3+ ions, respectively. The peak potentials at -2.20 and -0.168 V are the oxidation peaks of lanthanum and nickel, respectively. When potential is more negative than -1.74 V, La(Ⅲ) and Ni(Ⅱ) will codeposit. Increasing cyclic times, the value of peak current is decreasing, and the reduction peak of La(Ⅲ) was finally disappeared.

关键词： lanthanum codeposition dimethylsulfoxide La-Ni alloy powders rare earths

Pulse Plating of Copper-ZrB_(2) Composite Coatings

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Journal of Materials Science & Technology 2006年第4期22卷 514-518页

作者： Dongming GUO Min ZHANG Zhuji JIN Renke KANG Key laboratory for Precision ＆ Non-traditional Machining of Ministry of Education Dalian University of Technology Dalian 116023 China

Copper-zirconium diboride （ZrB2） composite coatings were fabricated using pulse plating technique to acquire a new type of EDM （electro-discharge machining） electrode material. The effects of pulse parameters, i.e., the average current density, the frequency and the duty cycle, on the incorporation of ZrB2 particles in the copper matrix were investigated. The amount＇of codeposited ZrB2 particles had a maximum at average current density of 3 A/din2 and increased with decreasing duty cycle as well as current frequency of the pulse current used for deposition. The hardness of the coatings increased with increasing ZrB2 percentage, whereas the incorporation of ZrB2 particles had little effect on the resistivity of the composites.

关键词： Pulse plating codeposition Composite coatings

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中国有色金属学会会刊：英文版 2001年第6期11卷 942-945页

作者： Yuang, DS Huang, KS Liu, GK Tong, YX Sa, LC Zhongshan Univ Sch Chem & Chem Engn Guangzhou 510275 Peoples R China

Potentiostatic and pulse electrolysis techniques were used to prepare La-Co-Fe alloy films using ethylenediamine (EN) as complexant. Surfaces of alloy films obtained by these two techniques are smooth, adhesive, compact and metallic luster. The contents of La in alloy films obtained by potentiostatic electrolysis technique are in the range of 13.23%～47.67%. The contents of La in alloy films deposited by pulse electrolysis technique are in the range of 10.67%～16.29%.

关键词： ethylenediamine lanthanum codeposition dimethylsulfoxide La-Co-Fe alloy films

Electrochemical behavior of electroplated Zn-P alloy

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中国有色金属学会会刊：英文版 2001年第4期11卷 603-605页

作者：张昭 Zhejiang Univ Dept Chem Hangzhou 310027 Peoples R China

The electroplating behavior of Zn P alloy on copper from light acid chloride solutions (LACS) was investigated using cyclic voltammetry and linear potential sweep method. It is found that, under the experimental conditions, the concentrations of H 3PO 3 and ascorbic acid in LACS change the codeposition mechanism of Zn P alloy, the addition of H 3PO 3 into LACS promotes the three dimentional (3 D) instantaneous nucleation/growth, while the addition of ascorbic acid promotes the two dimentional (2 D) instantaneous nucleation and layer by layer growth. H 3PO 3 and zinc ions inhibit the deposition each other. The experimental results also show that H 3PO 3 in the LACS can be reduced on the cathode individually, and low pH value of the LACS promotes the reduction of H 3PO 3.

关键词： Zn P alloy codeposition electrochemical behavior

Preparation and oxidation behaviour of electrodeposited Ni-CeO_2 nanocomposite coatings

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Transactions of Nonferrous Metals Society of China 2013年第7期23卷 2011-2020页

作者：张海军周月波孙俭峰黑龙江科技学院材料科学与工程学院哈尔滨150027

Ni-CeO2 nanocomposite coatings with different CeO2 contents were prepared by codeposition of Ni and CeO2 nanoparticles with an average particle size of 7 nm onto pure Ni surfaces from a nickel sulfate. The CeO2 nanoparticles were dispersed in the electrodeposited nanocrystalline Ni grains （with a size range of 10-30 nm）. The isothermal oxidation behaviours of Ni-CeO2 nanocomposite coatings with two different CeO2 particles contents and the electrodeposited pure Ni coating were comparatively investigated in order to elucidate the effect of CeO2 at different temperatures and also CeO2 contents on the oxidation behaviour of Ni-CeO2 nanocomposite coatings. The results show that the as-codeposited Ni-CeO2 nanocomposite coatings have a superior oxidation resistance compared with the electrodeposited pure Ni coating at 800 °C due to the codeposited CeO2 nanoparticles blocking the outward diffusion of nickel along the grain boundaries. However, the effects of CeO2 particles on the oxidation resistance significantly decrease at 1050 °C and 1150 °C due to the outward-volume diffusion of nickel controlling the oxidation growth mechanism, and the content of CeO2 has little influence on the oxidation.

关键词： codeposition nanocomposite coating oxidation reactive-element effect