Study Of The Electrical Structure Regulation And Properties Of The Nickle-iron Based Catalytic Electrode

Hydrogen energy has been incorporated into the strategic layout of new energy as an ideal secondary energy source.In recent years,hydrogen energy development has moved into the fast lane in our nation and has entered the crucial stage from demonstration application to large-scale application.Water cracking technology,which is an ideal sustainable hydrogen production method,can realize green hydrogen production and address the issues of energy scarcity and environment pollution.However,the sluggish oxygen evolution reaction（OER）,which is generally believed to involve the four-electron mechanism and requires high overpotential,and severely hinders the energy conversion of the electrolytic water process.Therefore,the current study focuses on how to create high efficiency and low overpotential OER catalyst to achieve optimum water oxidation.In this paper,NiFeLDH catalytic electrode,Ti@Ni（OH）₂/FeOOH heterojunction electrode and Ti@Fe₂（Mo O₄）₃@Ni（OH）₂heterojunction electrode were prepared on the basis of nickel（Ni）and iron（Fe）elements.By measuring,the oxygen evolution characteristics and enhancing mechanism were investigated.Other methods were employed to analyze the microstructure,component distribution,and valence changes of the catalyst during the reaction process.The primary research findings are as follows:（1）Electrochemical deposition was used to create NiFeLDH nanoarray catalyst.A NiFeLDH/Fe catalyst electrode with deposition time of 80 s acted directly as the anode electrode,providing a current density of 10 m A cm^-2at 1.455 V vs.RHE.At the same time,the catalyst also shows high stability.XPS results show that the coupling interface between the active site Fe and the collector（NiFeLDH）can adjust the local electronic structure of layered double hydroxide（LDH）to facilitate charge transfer.The synthesis of integrated electrodes can efficiently increase the conductivity of LDHs,making the production of the electrodes more straightforward,and reduce the time required to create the synthesis catalyst.（2）The interfacial Ti@Ni（OH）₂/FeOOH self-supported heterogeneous catalyst with low charge-transfer resistance and a current density of 10 m A cm^-2at 1.503 V vs.REH was created via solvothermal technique and electrochemical deposition.The Tafel slope is 42.9 m V dec^-1.At the same time,the catalyst showed no obvious attenuation following the 48 h stability test.The XPS results showed that there was charge transfer between Ni（OH）₂nanosheets and FeOOH nanoparticles,which significantly enhanced the adsorption capacity of the OER reaction intermediate.The construction of self-supported heterojunction catalyst is beneficial to the synergistic effect between Ni and Fe,thus improving the kinetics of water oxidation.（3）Porous nanoscale Ti@Fe₂（Mo O₄）₃@Ni（OH）₂heterojunction catalysts were prepared by two step solvothermal methods.The cayalyst is composed of Fe₂（Mo O₄）₃prisms and Ni（OH）₂nanoflowers.The mass transfer rate is enhanced by the increased active area that this nanostructure offers,which is conducive to complete contact between the active substances and the electrolyte.At 1.0 M KOH,a current density of 10 m A cm^-2with a Tafel slope of 56 m V dec^-1can be output at 1.480 V vs.RHE.The findings indicate a correlation between improved electrochemical performance and a rise in electrolyte temperature that is positive.The XPS results demonstrate a synergistic interaction between the elements Ni,Fe,and Mo,and the reaction kinetics is relatively quick.The investigation shows that the Fe₂（Mo O₄）₃@Ni（OH）₂precatalyst was rebuilt during the continuous OER catalytic process to create the new active substances FeOOH and Ni OOH as the actual active sites.