Controllable Synthesis Of Ru-Modifid Cobalt Phosphide Nanomaterials And Their Electrocatalytic Performance

In recent years,the problem of energy shortage and environmental pollution has become more and more serious,and the search for alternatives to traditional fossil fuels has become the focus of attention.As a new energy with excellent environmental protection and high energy density,hydrogen energy has been widely concerned.Among them,electrolytic water hydrogen production is considered the most promising way because of its convenience,high efficiency,and high product purity.At present,the most efficient catalyst for hydrogen production by electrocatalysis is noble metal-based catalyst,but its high cost limits the large-scale commercial development of hydrogen production by electrocatalysis.Therefore,in order to promote the commercialization of hydrogen production by water electrolysis,it is urgent to develop cost-effective non noble metal catalysts.Metal phosphide has been proved to be an efficient non noble metal electrocatalyst for hydrogen production.Ruthenium,as a precious metal,has good electrocatalytic hydrogen evolution performance,and its price is much lower than that of platinum.Based on this,cobalt phosphide-based catalysts with different morphologies were prepared by using the principle of hydrolysis and deposition of ruthenium chloride hydrate.The main research work and results are as follows:?1?Nitrogen doped carbon coated cobalt phosphide?Co P/NC?was synthesized by pyrolysis of ZIF-67 in nitrogen atmosphere.On this basis,Ru³⁺was attached to Co P/NC by hydrolysis deposition of Ru Cl₃ solution,and then reduced to Ru-Cop/NC by sodium borohydride.The catalyst shows good electrocatalytic hydrogen evolution performance in a wide range of p H electrolytes.?2?A kind of nitrogen doped carbon coated nickel cobalt phosphide nanocomposite Ni Co P/NC was synthesized by carbonization and phosphating at high temperature,adding a certain proportion of Ni into ZIF-67 by the effect of MOF multi-channel and confinement for MOF.In order to improve HER properties,a small amount of precious metal Ru was fixed on Ni Co P/NC by the principle of Ru³⁺hydrolysis-etching at room temperature.The catalyst showed excellent dual function catalytic performance by adjusting the feeding ratio of nickel and cobalt and introducing trace Ru successfully.In 1.0m KOH solution,the potential corresponding to the current density of 10 m A cm^-2 was 1.55 V when used for catalytic oxydrogen evolution reaction?OER?,and the over potential corresponding to the current density of 10 m A cm^-2 was 90 m V when used for HER?3?The nanoneedle array of Co?OH?F/CC was synthesized on carbon cloth by hydrothermal method,and then Co₃O₄/CC was obtained by pyrolysis at 300?in air,and then it was impregnated with Ru Cl₃ solution and calcined for 2 h with sodium hypophosphite as phosphorus source to obtain Ru Co P/CC nanoneedle array catalytic electrode.The electrocatalytic hydrogen evolution reaction was used as a model reaction to study its catalytic performance.The results showed that Ru,on the one hand,as an active site,greatly improved the performance of Co P/CC,on the other hand,the hydrolysis etching of Ru Cl₃ solution made the catalyst surface rougher,which was conducive to exposing more active sites and improving the catalytic performance.