Research On Membrane Electrode Based On AC Impedance Technology

AC impedance technology is a very important research method in electrochemical testing technology.It has developed very rapidly in recent decades and has become an important means of studying electrode process dynamics and surface phenomena.The scope of application has exceeded the field of electrochemistry and is becoming more and more widely.At present,there are many applications of AC impedance technologies,such as research on electrode processes,metal corrosion mechanisms and corrosion resistance,and performance evaluation of corrosion inhibitors in the field of electrochemistry;research on the performance of biofilms in the field of biology;The performance of conductive materials,etc.;in materials science,the mechanical properties of materials and the performance evaluation of materials after surface modification are studied.The application of AC impedance technology to the study of the reaction process of the surface of the metal electrode,on the basis of the measured impedance spectrum curve,the equivalent circuit analysis is carried out,and the structure of the electric double layer,the state of the electrode interface,etc.Analysis,so as to analyze and understand the quality of the electrolyte.Traditional electrochemical methods can only study the performance of metal surface films,but the research on the film formation process is limited.The AC impedance method can measure a wide range of impedance spectra to study the electrode system,and can obtain more dynamic information and interface structure information than conventionalmethods.The main research contents of this paper are as follows:1)Using the equivalent circuit and linear fitting of EIS,it is found that the diffusion process of the bare electrode and the graphene modified electrode is divided into spherical diffusion and planar diffusion,and the platinum nanoparticle/graphene modified electrode only has spherical diffusion.The negatively charged groups on the graphene surface will hinder the charge transfer on the electrode surface.After the platinum nanoparticles are incorporated,the charge transfer speed is greatly accelerated,indicating that the platinum nanoparticles have good catalytic activity.2)Using cyclic voltammetry to perform electrochemical deposition of Prussian blue film in two electrolytes with different compositions,observe the cyclic voltammetry behavior,and compare the AC impedance of the two films.The AC impedance measurement results of the Prussian blue film modified electrode show that the deposition conditions and the thickness of the deposited film have an effect on the charge transfer process.3)The cyclic voltammetry was used to study the redox process of the phospholipid bilayer membrane supported by platinum electrode during the preparation process;using the results measured by AC impedance technology,the action time and DSB concentration were discussed.The effect of bilayer membrane interaction;Observing the self-healing process of the interaction between DSB and supporting phospholipid bilayer membrane,it was found that the effect between DSB and supporting phospholipid bilayer membrane was reversible.