In situ Grown Pyramid Structures of Nickel Diselenides Dependent on Oxidized Nickel Foam as Efficient Electrocatalyst for Oxygen Evolution Reaction

By Li, Xiao; Han, Guan-Qun; Liu, Yan-Ru; Dong, Bin; Shang, Xiao; Hu, Wen-Hui; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang
Published in Electrochimica Acta NULL 2016

Abstract

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.

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