ZHANG Tao, WANG Yuying, CHEN Longxia, TANG Huiqin, LI Min, ZHANG Jie, LIU Zitang
After liquid phase oxidation modification of carbon materials with concentrated nitric acid, phosphoric acid, hydrogen peroxide, etc., carbon microporous layer was made with PTFE, dispersant, etc. The influence of modification on the performance of carbon layer was studied, mainly including the thermal stability of carbon, the particle distribution of modified carbon in the slurry, the surface structure of carbon layer and the reaction impedance of membrane electrode, etc. Thermogravimetric analysis, SEM, FTIR, XRD, BET, particle size analysis and EIS were used to characterize the properties and pore-forming structures of carbon, and to analyze the effects of different treatment methods on the functional groups of carbon surface. It is found that after treatment, the types of oxygen-containing groups on the surface of carbon increased, the peak temperature decreased, and the thermal stability deteriorate, but hydrophile groups are formed on the surface of carbon, and the dispersion becomes better. Through the analysis of the microstructure of the carbon layer particles, it is found that the surface modification of the oxidizing liquid has an effect on the pore channel structure of the carbon microporous layer, and the electrochemical performance of the carbon layer treated with nitric acid is relatively good.
