The Synthesis Of Efficent Ni-based Oxygen Evolution Electrocatalyst Under Neutural Conditions By Micro-arc Oxidation

With the increasingly serious energy crisis and environmental problems,people urgently need a clean and efficient energy.Hydrogen energy has attracted more and more attention because of its high energy density,pollution-free combustion products,and abundant earth reserves.Electrolyzed water is currently the most promising method for hydrogen production,but the excessive oxygen evolution overpotential of the anode will cause a large amount of energy loss.It is of great significance to develop low-cost,high-activity and high-stability electro-oxygen evolution catalysts.Electrolyzed water in a neutral environment has broad application prospects.However,compared with the alkaline environment,the energy barrier of the oxygen evolution reaction in the neutral environment is greater,and the requirements for the catalyst are higher.The transition metal phosphate is a kind of electrocatalyst suitable for oxygen evolution in a neutral environment.It has a good ability to receive and transfer protons.It can promote the adsorption and desorption of oxygen-containing intermediates,but its ability to promote water decomposition is poor.Transition metal oxides have the ability to efficiently promote the decomposition of water,which is conducive to the formation of adsorbed hydroxyl groups in the oxygen evolution reaction,but it is not an effective proton acceptor and it is difficult to receive and transfer protons generated in the oxygen evolution reaction.The composite electrode material can effectively combine the advantages of each component and obtain a good oxygen evolution activity,but currently faces problems such as cumbersome preparation process,difficult composition control,and poor binding force between components.In response to the above problems,this subject introduced micro-arc oxidation technology into the preparation of nickel-based oxygen evolution electrocatalysts for the first time,and studied the effects of different solution systems and process parameters on the phase,composition and surface morphology of nickel-based micro-arc oxidation films.Ni Pi/Ni O composites with"eggshell-like"morphology were prepared.In addition,using ethylene glycol as the organic carbon source,Ni Pi/Ni O carbon coating was achieved,and Ni Pi/Ni O@C was prepared,which significantly improved the conductivity,catalytic activity and stability of oxygen evolution.In 0.1mol/L PBS solution,the over potential of Ni Pi/Ni O@C is 655m V under 10m A cm^-2oxygen evolution current.After 24h stability test,its catalytic activity has not been significantly attenuated,and its comprehensive performance is better than the most of the non-noble metal oxygen evolution catalysts reported in the neutral environment.Good ability to receive and transfer protons and promote water decomposition,large active specific surface area,and good charge conductivity are the main reasons for its high catalytic activity.This study provides a new method for preparing nickel-based oxygen evolution electrocatalyst,and studies the structure-activity relationship of the oxygen evolution catalyst under neutral conditions.The preparation process of this subject is simple,fast,and has good regulation and control,which is convenient for mass production.The prepared catalyst has excellent activity and stability,which can provide reference and reference for the practical application of electrolytic water.