Preparation Of Nickel-based Composite Nanofibers And The Study Of Their Electrocatalytic Oxygen Precipitation Properties

The consumption of fossil fuels has caused huge greenhouse effect and environmental pollution,and its limited reserves can not meet the requirements of rapid and substantial development of society,which has stimulated the in-depth research on renewable energy and clean energy to replace traditional fossil fuels.Hydrogen is an ideal candidate to replace fossil fuels because of its high energy density,environmental protection and sustainability.Hydrogen is a promising alternative energy source.Overall Water Splitting is the most promising technology for large-scale hydrogen production.It is a useful way to convert chemical forms and store renewable energy.Oxygen evolution reaction（OER）is one of the most basic and important reactions in many fields such as water cracking and rechargeable metal-air batteries.In general,the reaction kinetics is slow and overpotential is high,so efficient catalysts are required.Among them,precious metals IrO₂and RuO₂have high OER performance,but their practical application is hindered by high yield scarcity cost.In addition,IrO₂and RuO₂are easily oxidized during the reaction process,leading to degradation of catalytic activity and increase of overpotential.Therefore,alternative electrocatalysts are indeed needed to make OER more practical.Therefore,a great deal of research work is devoted to the production of low-cost,earth-rich,excellent performance of electrocatalysts.Currently,electrospun nanomaterials are widely used in storage and energy conversion due to their large specific surface area,unique structure and fast electron and matter transfer.At the same time,nickel-based transition metal compounds have been widely studied as electrocatalysts for oxygen evolution reaction.In this paper,the preparation and electrochemical oxygen evolution performance of nickel matrix composites are studied.（1）Firstly,one-dimensional MnNi₂O₄nanofibers were obtained by electrostatic spinning method,and one-dimensional Ni₂P/Mn₂O₃composite nanofibers were obtained by phosphating MnNi₂O₄nanofibers by tubular furnace method.The one-dimensional structure of the composite is conducive to increase the electrochemical active surface area and expose more active sites.The synergistic effect of Ni₂P and Mn₂O₃makes Ni₂P/Mn₂O₃composite nanofibers exhibit excellent OER activity.Whenthe current density is 10 m A cm^-2,the overpotential of Ni₂P/Mn₂O₃composite is only 280 m V,the tafel slope is 119.8 m V dec^-1,Ni₂P/Mn₂O₃nanofibers have a good durability.This study indicates that the phosphating material of nickel metal can be used in the direction of electrocatalyst and has good properties.（2）Secondly,one-dimensional MnNi₂O₄nanofibers were obtained by electrostatic spinning,and one-dimensional NiS₂/NiS/Mn₂O₃composite nanofibers were obtained by sulfurization of MnNi₂O₄nanofibers in tubular furnace.In 1 M KOH electrolysis solution,when the current density of the composite nanofiber is 20 m A cm^-2,the required overpotential is only 333 m V and the tafel slope is 155.1 m V dec^-1.This kind of catalyst shows a good performance of electrocatalytic oxygen evolution and has a good application prospect in the direction of electrolytic water oxygen evolution.