Bio-template Assisted Preparation Of Nickel Based Hydroxide Films And Their Performance For Electrocatalytic Oxygen Evolution Reactions

Loading oxygen evolution reaction?OER?catalysts can decrease the OER overpotential,which is crucial for the enhancement of the efficiency of solar photoelectrochemical water splitting processes.Nickel-based hydroxide?NBH?is an OER catalyst that is currently attracting extensive attention.However,the key factors which affect the electrocatalytic activity are not yet clear.Aming at optimizing the OER performance of the NBH films,biotemplates were used in this dissertation research to modify the structure of the films.In order to reveal the influence mechanisms of sample structures on the OER activity,the structures and carrier transport dynamics of the samples were studied by using a series of techniques which mainly includes Field Emission Scanning Electron Microscopy?FESEM?,X-ray Powder Diffraction?XRD?,Fourier Transform Infrared Spectroscopy?FT-IR?,Electrochemical Impedance Spectroscopy?EIS?,Cyclic Voltammetry?CV?and Chronoamperometry?i-t?,and etc..Based on this influence mechanism,Ni?OH?₂/Fe₂O₃photoanode films with much higher visible-light activity were prepared.The research content mainly includs the following three parts:1.Exploring at molecule-scale level the influence of biomolecules that act as the modifiers ofthe coordination structure of the active sites in catalysts on the performance of the films.?1?Screening biomolecules that can act as the structural modifiers of the catalytic site;?2?Optimizing experimental parameters including the dosage of biomolecules and electrochemical deposition conditions.2.Controlling the structures of the Ni?OH?₂ films at nanometer and micrometer scales with S.aureus and E.coli flagella as the biotemplates.?1?The chemical interactions between the surface functional groups of the microbial biotemplates and the catalytic active site,that is,the nickel atoms;?2?Biotemplate-assisted formation of the porous nanostructure and its influence on the electrochemically active surface area of the films.3.The influence mechanisms of the carrier dynamics on the OER activity,and with these mechanisms as instruction to prepare Ni?OH?₂/Fe₂O₃ photoanode films with enhanced photoactivity.