非晶态NiP基催化剂的制备及电催化析氢性能研究

摘要

以NaH2PO2和Ni2SO4为磷源和镍源,使用一锅法合成了非晶态NiP合金及其碳纳米(乙炔黑和石墨烯)复合催化剂.用透射电子显微镜(TEM)、X射线衍射仪(XRD)、热重分析(TGA)、电感耦合等离子体光谱仪(ICP)分别对催化剂性能和组成进行了表征和分析.通过线性扫描伏安对催化剂在酸性和碱性条件下的析氢性能进行了评价,研究结果表明,非晶态NiP/还原氧化石墨烯复合催化剂(NiP/RGO)展现出优异的电催化性能.在0.5 mol/L H2SO4中的起始过电位为89.0 mV,塔菲尔斜率为135.1 mV /decade;在1 mol/L NaOH中,起始过电位为116.1 mV,塔菲尔斜率为122.4 mV /decade,这与商业化Pt黑催化剂很接近.500次循环以后,催化剂活性没有明显下降,表明该催化剂具有良好的稳定性.该研究提供了一种简单可行的制备非贵金属磷化物方法用于电催化析氢反应.%Amorphous alloy NiP and its carbon composite catalysts NiP/C and NiP/reduced graphene oxide (RGO) were successfully one-pot synthesized using NaH2PO2and NiSO4as phosphorus and nickel source,respectively. The electrocatalysts were characterized with transmission electron microscope (TEM), X-ray diffraction spectrometer (XRD), inductively coupled plasma analysis (ICP) and thermogravimetric analysis (TG), respectively. The hydrogen evolution reactions (HER) performance of the electrocatalysts was evaluated with a linear sweep voltammetry method in both acidic and alkaline solution. Among them,NiP/RGO elctrocatalyst exhibited 89.0 mV onset overpotential and Tafel slope 135.1 mV/decade in acidic solution,as well as 116.1 mV onset overpotential and Tafel slope 122.4 mV/decade in alkaline solution with excellent long-term stability. Results indicated that the NiP/RGO was a very active catalyst.