In situ Grown Pyramid Structures of Nickel Diselenides Dependent on Oxidized Nickel Foam as Efficient Electrocatalyst for Oxygen Evolution Reaction
By Xiao Li and Guan-Qun Han and Yan-Ru Liu and Bin Dong and Xiao Shang and Wen-Hui Hu and Yong-Ming Chai and Yun-Qi Liu and Chen-Guang Liu
Published in Electrochimica Acta
2016
Abstract
In situ grown pyramid structures of nickel diselenides (NiSe2) have been synthesized using oxidized nickel foam (NF (Ox)) as substrate by a facile solvothermal selenization. \XRD\ results show that NiSe phase on \NF\ and NiSe2 phase on \NF\ (Ox) have been obtained after the identical selenization process, respectively. The nanorods morphology of NiSe on \NF\ and pyramid structure of NiSe2 on \NF\ (Ox) have been revealed by \SEM\ images. The different structure and morphology of NiSe/NF compared with NiSe2/NF (Ox) can be ascribed to the oxidation pretreatment of \NF\ which affiliates the formation of ultrathin ?-Ni(OH)2 nanosheets on NF. The electrochemical measurements for oxygen evolution reaction (OER) exhibit an enhanced electrocatalytic activity of NiSe2/NF (Ox) with onset potential of 1.54 V (vs. RHE) and small Tafel slope of 96 mV dec?1. Moreover, NiSe2/NF (Ox) possesses lower charge-transfer resistance (Rct) indicating a faster electron transfer rate than NiSe/NF. The excellent stability further confirms the improved elctrocatalytic performance of NiSe2/NF (Ox). We speculate that the high Ni2+ proportion and octahedral structure of NiSe2 may be the keys for excellent electrocatalytic properties for OER.