In situ growth of NixSy controlled by surface treatment of nickel foam as efficient electrocatalyst for oxygen evolution reaction
By Xiao Shang and Xiao Li and Wen-Hui Hu and Bin Dong and Yan-Ru Liu and Guan-Qun Han and Yong-Ming Chai and Yun-Qi Liu and Chen-Guang Liu
Published in Applied Surface Science
2016
Abstract
In situ growth of NixSy with different crystal phases supported on different surface-treated (acidification or oxidation) nickel foam (NF) has been successfully achieved by a facile solvothermal process. \XRD\ and \SEM\ results show that crystal phase and morphology of NixSy have been greatly affected by the surface treatment of NF. \XRD\ results show that the mixture crystal phases of NixSy have been obtained on both acid-treated \NF\ (NF(a)) and oxidant treated \NF\ (NF(o)). NixSy/NF(a) contains Ni3S2 and NiS, whereas NixSy/NF(o) has Ni3S2 and NiS2, implying different crystal phases derived from different surface treatment of NF. \SEM\ images also reveal the different morphology of two samples based on pre-treatment support. NixSy/NF(a) displays unique conical agglomeration surrounded by porous structure. NixSy/NF(o) has the disorder stacking structure of nanosheets. Electrochemical measurements for oxygen evolution reaction (OER) show the enhanced performances of NixSy/NF(a) than NixSy/NF(o) and pure Ni3S2/NF as contrast samples, implying that NiS outperforms other types of NixSy. The mechanisms of sulfurization path of different surface-treated \NF\ have been discussed. The facile surface treatment of \NF\ may provide a new strategy to prepare excellent electrocatalysts for OER.