无定形NiCoSe电极的碱性电解水析氢性能

Hydrogen evolution performance of amorphous NiCoSe electrode for alkaline electrolysis of water

采用电沉积法在镍丝网上合成Ni、Co共掺杂的无定形硒化物NiCoSe作为析氢催化剂电极,利用扫描电镜、X射线衍射仪、透射电镜、X射线光电子能谱仪等观察和分析NiCoSe电极的形貌与结构,通过电化学实验测试电极的电催化析氢性能。结果表明,NiCoSe电极表面镶嵌着球形NiCoSe颗粒,无明显裂纹。NiCoSe化合物为无定形状态,能提供更多的低能垒空穴。适当比例的Ni、Co共掺杂可对Se的电子结构进行调控,使催化剂的电子结合能发生偏移,进而增强催化剂对H原子的吸附能力,使NiCoSe析氢催化剂电极具有较高的本征催化活性。在1 mol/L KOH溶液中10 mA/cm2电流密度下,NiCoSe阴极的过电位为83 mV,塔菲尔斜率为108.98 mV/dec,控制反应速率的步骤为催化剂对H原子的吸附过程。在60 h电解后电流密度衰减率小于5%。

Ni and Co co-doped amorphous selenide was synthesized on nickel mesh as hydrogen evolution catalyst electrode by electrode position method,and the morphology and microstructure of NiCoSe electrode were observed and analyzed by scanning electron microscopy,X-ray diffractometer,transmission electron microscopy and X-ray photoelectron spectrometer,and the electrocatalytic hydrogen evolution performance of the electrode was tested by electrochemical experiments.The results show that the NiCoSe electrode surface is embedded with NiCoSe spherical particles,and no obvious cracks.NiCoSe compound is amorphous and can provide more low-energy barrier cavities.The appropriate ratio of Ni and Co co-doping can modulate the electronic structure of Se to shift the electronic binding energy of the catalyst,which in turn enhances the adsorption ability of the catalyst to H atoms,resulting in a higher intrinsic catalytic activity of the NiCoSe hydrogen evolution catalyst electrode.At a current density of 10 mA/cm2 in 1 mol/L KOH solution,the overpotential of the NiCoSe cathode is 83 mV,and the Tafel slope is 108.98 mV/dec.The step controlling the reaction rate is the adsorption process of the catalyst on H atoms.The current density decay rate is less than 5%after 60 h electrolysis.