Controllable synthesis of three dimensional electrodeposited Co-P nanosphere arrays as efficient electrocatalysts for overall water splitting

By Han, Guan-Qun; Li, Xiao; Liu, Yan-Ru; Dong, Bin; Hu, Wen-Hui; Shang, Xiao; Zhao, Xin; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang
Published in RSC Adv The Royal Society of Chemistry 2016

Abstract

Novel three dimensional (3D) electrodeposited Co-P nanosphere arrays on FTO (Co-P/FTO) have been successfully prepared as efficient bifunctional electrocatalysts for overall water splitting in alkaline media. The morphologies and properties of the 3D Co-P nanosphere arrays can be controlled by the electrolyte concentration. At the middle concentration, Co-P nanospheres have a more homogeneous size and array distribution and a rough surface, implying a larger surface area and an increased number of active sites for water splitting. The electrochemical measurements confirm the best electrocatalytic performances of Co-P/FTO at the middle concentration. They show excellent activity, with an overpotential of 125 mV for HER, 420 mV for OER and Tafel slopes of 54 mV dec-1 and 83 mV dec-1, respectively. The fabricated bifunctional systems of Co-P/Co-P can efficiently catalyse HER and OER at the same time, solving the incompatible problem of different media between HER and OER. Therefore, controlling the synthesis of 3D Co-P/FTO nanosphere arrays through electrodeposition can provide a facile way for the bifunctional electrocatalysis of both HER and OER.

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