Preparation And Electrocatalytic Hydrogen Evolution Of Nickel-based Composite Electrode

At present,due to the large-scale use of traditional fossil fuels such as coal,petroleum,and natural gas in industrial production and people’s lives,the energy crisis and environmental pollution problems have become increasingly serious.Therefore,the exploration of clean,efficient and renewable new energy technologies is imminent.As an ideal alternative to fossil fuels,hydrogen has the advantages of abundant resources,high heat of combustion,and environmental protection.Among many hydrogen production technologies,electrolysis of water is the safest and most reliable method of hydrogen production,and it is widely used in industrial production.However,the presence of high hydrogen evolution overpotentials in the electrolysis process has become the biggest problem that restricts its development.Hence,selecting a highly catalytically active electrode material and effectively increasing its specific surface area and electrical conductivity is the most effective method for reducing the hydrogen evolution overpotential.The nickel-based hydrogen evolution electrode prepared by the high-gravity electrodeposition has excellent catalytic activity and good electrical conductivity.However,the nickel particles are easily agglomerated during the electrodeposition process.While the addition of the two-dimensional material can effectively inhibit the agglomeration of nickel particles and expose more hydrogen evolution active sites,which provide a new idea for the preparation of high-efficiency electrodes by electrodeposition.The content of this paper is as follows:Ni-MoS₂ composite electrodes has been synthesized under supergravity fields on copper and nickel foams,respectively,and their electrocatalytic hydrogen evolution properties were studied.The results showed that with foaming as a substrate,the MoS₂ addition amount was 0.8 g L^-11 showing a very low hydrogen evolution overpotential.At a current density of 100 mA cm^-2,the overpotential was only 207mV,and the very small Tafel slope was 65 mV dec^-1.This is mainly due to the fact that the three-dimensional porous structure of the foamed nickel substrate can provide a larger specific surface area than the copper substrate.Moreover,proper MoS₂addition can effectively inhibit the agglomeration of the nickel particles during the electrodeposition process and further expose more hydrogen evolution.Active micro points.Ni-MoS₂,Ni-GO and Ni-（MoS₂/GO）composite electrodes were prepared under supergravity fields on the basis of foam Ni,and their electrocatalytic hydrogen evolution properties were studied.Compared to MoS₂ and GO alone,the addition of MoS₂/GO can further refine and disperse the nickel particles,which effectively increases the specific surface area.The Ni-（MoS₂/GO）composite electrode exhibits excellent electrocatalytic hydrogen evolution performance.At a current density of 100mA cm^-2,the overpotential was only 132 mV.At the same time,the Tafel slope was110 mV dec^-1.In addition,the electrode exhibits superior cycle stability after a long period of hydrogen evolution reaction.