The Construction Of Highly Efficient Transition Metal-based Catalysts

Energy is very important for human survival and promotse the development of national economy and society.Hydrogen（H₂）is a clean,renewable energy carrier and a promising alternative to fossil fuels in future.Hydrogen production from electrocatalytic water splitting is one of the most efficient way at present,which is divided into two half reactions,namely anode oxygen evolution reaction（OER）and cathode hydrogen evolution reaction（HER）.However,these reactions with sluggish kinetics are usually needed to be operated in the presence of efficient electrocatalysts to overcome the energy barriers.Currently,noble metal-based catalysts are recognized as the state-of-the-art HER electrocatalyst,but their high price and valuableness impede their applications.Therefore,it is imperative to develop an efficient and cheap electrocatalyst to substitute the noble metals catalyst.Ttransition metal materials（Fe,Co,Ni）have low price,high conductivity and high ability as well as the electronic structure and catalytic ability similar to platinum,Therefore,it has been extensively employed as robust electrocatalyst for the full water splitting.In this dissertation,transition metal Co,Cr,V,Ni based catalysts are constructed by electrodeposition,solvothermal and pyrolysis methods.Here,foamed copper and carbon cloth are selected as the substrate,and three types electrocatalyst for HER and OER are prepared.Specifically,it is divided into the following three parts:First,Cr Co LDH supported on copper foam for HER and OER is synthesized by using the method of electrodeposition.Also,the morphology and the performance is tuned by adjusting the proportion of metal addition;Second,using V and Co as experimental materials,the copper hydroxide nanowire on copper foam is synthesized electrodepositon method,the Co V/Cu（OH）₂ catalyst is prepared by using a hydrothermal method.Due to its sheet structure to expose more active site,so it has excellent catalytic activity;Thirdly,the active Ni Fe-P-O for OER is prepared by solvothermal-phosphating-oxidation method.Different nickel sources are used to prepare MOFs,it is found that the morpholy of MOFs is distinct from each other by selecting different nickel salts,which impacts the activity.Furthermore,the catalytic activity for OER is optimized by oxidation the phosphide.Finally,the morphology and structure of the materials were analyzed by SEM,TEM,XRD and XPS.The electrochemical properties of the materials were studied by using CV,LSV,i-t,EIS,ECSA and other electrochemical tests.The test results show that the three materials synthesized by us can be used as excellent electrolytic water catalysts.