Preparation Of Electrocatalyst Based On Iron-cobalt Metal Compound And Investigation Of Its Catalytic Performance For Oxygen Evolution Under Alkaline Conditions

H₂ is considered as one of the most promising energy carriers to replace fossil fuels,which has high energy efficiency and no pollution.Electrochemical decomposition of water is the most promising route for hydrogen production.The process of water electrolysis involves the hydrogen evolution reaction（HER）of the cathode and the oxygen evolution reaction（OER）of the anode.Among them,OER is a complex four-electron transfer reaction with high energy barrier and slow kinetics,which restricts the development of hydrogen production by electrolysis of water.The design of high performance OER electrocatalyst is a key step to solve the above problems.Among the many catalysts,the oxides of Ir and Ru show excellent catalytic activity for OER,but their scarcity and high cost make it difficult to be used on a large scale.In recent years,non-precious transition metal-based catalysts have attracted wide attention because of their low cost and abundant reserves.In this thesis,the electrocatalysts of non-noble transition metal-based compounds were used to prepare Au/Co-Fe OOH,FeCoS/C,metal sulphides and Fe-based metal-organic framework composites through a simple solution phase synthesis approach.The obtained catalysts were systematically characterized and their catalytic performance for water oxidation was investigated.The specific research contents are as follows:1.Au nanoparticles can produce hot electrons under light radiation,which can further optimize the catalytic activity of the catalyst.Taking Au/Co-Fe OOH composite catalyst as an example,the results show that the plasma effect of Au nanoparticles can enhance the catalytic activity of OER.Under the laser irradiation of 532 nm,the oxygen evolution overpotential of the optimized composite catalyst decreased from 386 m V to 309 m V at 10m A cm^-2.The reason for the increase in catalytic activity may be that hot electron excitation promotes the formation of more catalytic active species.2.FeCoS/C composites were synthesized by solvothermal method.A series of electrocatalysts were prepared by adjusting the solvothermal reaction time and the concentration of sulfur source.In 1 mol/L KOH electrolyte,the optimized catalyst can drive the current density of 10 m A cm^-2under the condition of 271 m V overpotential,and shows excellent catalytic stability.The catalysts after catalytic reaction were collected and characterized.It was found that in the process of oxygen evolution,some sulfides were oxidized in situ to form oxides or hydroxides,which were used as catalytic active phases.3.Metal sulfide/Fe-based metal organic skeleton composites were prepared based on foamed nickel.In alkaline electrolyte,the composite catalytic electrode showed significant catalytic activity,the overpotential was only 286 m V at the current density of 50 m A cm^-2,and the catalytic stability was good,which was stable for at least 48 h under the current density of 100 m A cm^-2.The excellent catalytic performance of the synthesized products can be attributed to the strong electron interaction between metal sulfides and Fe-based metal organic framework,which adjusts the catalytic active site to the electron-rich state,which enhances the adsorption of oxygen-containing intermediates and promotes the oxygen evolution reaction.