Investigation On Constructing High-Efficiency Water Splitting Catalyst Based On Oxygen Vacancy Defects

Fossil fuel resources are deemed to be limited and environmentally problematic,so it is crucial to find alternative clean energy sources.Hydrogen has attracted much attention due to its high energy density,extensive resources and environment friendly nature.Commercial HER and OER catalysts are generally Pt/C and IrO₂ or RuO₂ with a single function,but they cannot be commonly used because of their high cost,scarcity and lack of stability.The development of inexpensive,efficient and long lifetime electrocatalysts for water splitting is a great challenge.This article takes oxygen vacancies as the research object,and aims to develop and synthesize low-cost,high activity and high stability electrolytic water catalyst materials.The application direction of oxygen vacancies was explored,and a low-cost and efficient electrolytic water catalyst based on oxygen vacancy defects was synthesized using a simple method.The oxygen vacancy modified OER catalyst Ov-CuO/Cu-PBA was synthesized in liquid phase at room temperature.The composite has nanorod structure and abundant oxygen vacancy defects.The active material Cu-PBA was grown in situ on the Ov-CuO nanorods with excellent conductivity,which combined the advantages of the two.Moreover,this nanostructure is conducive to electron transport and exposure of more active sites.The electrochemical test results show that Ov-CuO/Cu-PBA has better activity for OER.The experimental results show that the oxygen vacancy in the system is to improve the conductivity of the system,the role of Cu-PBA in the system is as the catalytic activity center,Ov-CuO/Cu-PBA has better performance.An efficient method to prepare FeP by using oxygen vacancy was been designed.FeP with nano structure was synthesized by using oxygen vacancy as intermediate.By means of XRD,EDS,XPS and electrochemistry,the effects of oxygen vacancy defects on the phosphating process and the catalytic properties of Ov-FeP were discussed.In this study,iron oxide with defects of oxygen rich vacancy was synthesized,and its phosphating products have more Fe-P bonds on the surface.As an intermediate,oxygen vacancy can significantly improve the phosphating efficiency.The electrochemical test shows that Ov-FeP/IF has the best catalytic activity for hydrogen evolution.At the current density of 10 mA cm^-2,the overpotential is only40 mV.An abundant oxygen vacancy nanorod heterogeneous Ov-CoFe₂O₄/CoO_x HER electrocatalyst grown on nickel foam using a facile method.We demonstrated abundant oxygen vacancies and strong interfacial coupling effects between Ov-CoFe₂O₄ and Ov-CoO_x.The electronic conduction of Ov-CoFe₂O₄/CoO_x and its HER performance markedly increased.Ov-CoFe₂O₄/CoO_x/NF exhibited a small Tafel slope of 69 mV dec^-11 and a low overpotential of 59mV at a current density of 10 mA cm^-2.The experimental studies and theory calculation results reveal that oxygen vacancies and heterogeneity can optimize the electronic structure,thus dramatically enhancing the electron transmission rate and HER activity.This study provides a facile design for simultaneous realization of oxygen vacancy modification and heterostructure formation that can be used as a simple strategy for oxides to improve their HER performance.