Abstract:

Electrochemical water splitting is an important green hydrogen technology. The development of efficient and cost-effective electrocatalyst is the focus of current research. A novel hydrogen evolution reaction (HER) electrocatalyst NiCoP/rGO/NF was constructed by electroless plating on nickel foam substrate that was loaded with three-dimensional reduced graphene oxide (rGO). The electrocatalysis performance of NiCoP/NF and that with the introduction of rGO (NiCoP/rGO/NF) was compared. The test results of the three-electrode system showed that, in 1mol/L KOH electrolyte and under the current density of 10mA/cm², the NiCoP/rGO/NF electrode gave the highest overpotential of 98mV. The remarkable performance of NiCoP/rGO/NF electrode in HER might be the comprehensive result of fast reaction kinetics, large electrochemical active specific surface area (ECSA) and small reaction resistance (R_ct) as indicated by the Tafel, cyclic voltammetry (CV) and impedance (EIS) analysis. The structure characterization confirmed that NiCoP was deposited uniformly on the surface of rGO and NF, and the three-dimensional network structure formed by rGO increased the catalyst surface area and exposed rich active edges. The formation of the Ni—P/Co—P bond in NiCoP/rGO/NF was key of HER performance improvement.

Key words: electrochemistry, hydrogen production, catalyst, electroless plating, transition metal phosphide, three-dimensional graphene

摘要：

电解水制氢是一项制取绿色氢能的重要技术，而开发具有低成本、高活性的催化剂作为电极材料是当前的研究重点。本文以负载石墨烯的泡沫镍（rGO/NF）为基底，应用化学镀法制备了NiCoP/rGO/NF新型析氢（HER）电解水催化剂。比较NiCoP/NF和引入石墨烯后的NiCoP/rGO/NF的电催化性能。三电极体系的测试结果表明，在1mol/L KOH电解液中，在电流密度为10mA/cm²时，NiCoP/rGO/NF电极具有最优的过电位98mV。塔菲尔斜率（Tafel）、循环伏安（CV）和电化学阻抗（EIS）分析表明，NiCoP/rGO/NF电极优异的HER性能是快速反应动力学、高效电化学活性比表面积（ECSA）和小反应电阻（R_ct）综合作用的结果。结构测试表明：NiCoP均匀沉积于rGO和泡沫镍表面，并且rGO形成的三维网络结构增加了催化剂比表面积，暴露出丰富的活性边缘，催化剂中Ni—P/Co—P键的形成是HER性能提升的关键。

关键词: 电化学, 制氢, 催化剂, 化学镀, 过渡金属磷化物, 三维石墨烯