1. Oxygen evolution reaction on Ni-substituted Co3O4 nanowire array electrodes
- Author
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Lu, Bangan, Cao, Dianxue, Wang, Pan, Wang, Guiling, and Gao, Yinyi
- Subjects
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CHEMICAL reactions , *NANOWIRES , *ELECTRODES , *COBALT , *NICKEL , *FOAM , *SCANNING electron microscopy , *X-ray diffraction , *SURFACE roughness - Abstract
Abstract: Nanowire arrays of mixed oxides of Co and Ni freely standing on Ni foam are prepared by a template-free growth method. The effects of Ni content on the morphology, structure and catalyst performance for oxygen evolution reaction are investigated by scanning electron microscopy, X-ray diffraction spectroscopy and electrochemical techniques including cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. A transformation from nanowire arrays to nanoplate arrays is found with the increase of the atomic ratio of Ni to Co in the preparation solution. The NixCo3−xO4 electrode obtained at 1:1 of Ni:Co in the preparation solution exhibits nanowire array structure and has better catalytic performance for oxygen evolution reaction than other NixCo3−xO4 and Co3O4 electrodes. The catalytic activities of the NixCo3−xO4 and Co3O4 electrodes are correlated with their surface roughness. Superior stability of the NixCo3−xO4 nanowire array electrode is demonstrated by a chronopotentiometric test. The reaction orders with respect to OH− on the NixCo3−xO4 electrode are close to 2 and 1 at low and high overpotentials, respectively. [Copyright &y& Elsevier]
- Published
- 2011
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