Electrodeposition Of Cobalt Nickel Phosphosulfide Electrode On Carbon Fiber Paper And Its Electrocatalytic Performance Toward Water Oxidation

With the excessive consumption of traditional fossil fuels,the energy problem has become a global problem.The search for renewable,environmentally friendly energy is imminent.Water decomposition to produce hydrogen and oxygen is one of the most promising renewable energy conversion technologies,but its development is limited by four-electron transfer kinetics of anodic oxygen evolution reaction.It is very important to develop an efficient and stable catalyst for oxygen evolution reaction.In this study,cobalt phosphosulfides electrode and cobalt nickel sulfide phosphate electrode with better oxygen evolution activity were successfully synthesized by electrodeposition on the substrate of carbon fiber paper.Firstly,cyclic voltammetry（CV）electrodeposition method was used to prepare Cobalt phosphide,in which carbon fiber paper was used as substrate.The influence of the number of deposition circles on the surface morphology and catalytic activity of the catalyst was analyzed,after a long period of durability test about 40 h,the catalyst still maintained a good catalytic activity of oxygen evolution.In order to improve the catalytic activity of catalyst,non-metallic element S was added to search the influence of phosphosulfides to electrocatalyst.Co_2-xSP/CFP was prepared by two-step electrodeposition method in the same system.By changing the number of cycles of deposition,the surface morphology of the catalyst and the content of P element were regulated.The best catalyst for oxygen evolution was obtained,which was described as Co_2-xSP3/CFP.The overpotential of oxygen evolution of the catalyst is obviously lower than that of Co₂P/CFP and Co_1-xS/CFP.After 60 hours of stability test,the catalyst still shows good catalytic activity for oxygen evolution.The surface of Co_2-xSP/CFP was gradually oxidized to cobalt oxide/cobalt hydroxide.On the basis of Co_2-xSP,the Ni metal was doped into the catalyst to obtain Co₂Ni_2-xS_1-xP_x/CFP oxygen evolution catalyst.With the addition of Ni,the Co³⁺/Co²⁺ratio further improved in the catalyst and the oxygen evolution activity of the new catalyst was further improved.The stability of oxygen evolution is superior,at the same time,the catalyst has a good overall water performance.