Preparation Of Porous Carbon Materials Derived From Leather Wastes And Study On Electrochemical Properties

Global solid waste treatment is facing great challenges.How to turn waste into treasure is a research hotspot and an environmental protection problem that needs to be solved urgently.China is a big country of leather,and the comprehensive utilization of a large amount of leather waste needs to be solved urgently.Based on the research status of super capacitor,this paper puts forward with leather waste nitrogen doped porous carbon by precursors and the conductive polypyrrole was grown in situ with the material as the matrix,then the composites were prepared by secondary carbonization,finally,polypyrrole and Mo S₂ were loaded in situ on porous carbon matrix by chemical oxidation polymerization and solvothermal method respectively,which were used as positive and negative electrode materials to assemble asymmetric supercapacitors.This paper focuses on the preparation of nitrogen-doped porous carbon from waste leather scraps.The potential advantages of nitrogen-doped porous carbon,conductive polymer and transition metal disulfide in electrochemical energy storage are integrated to significantly increase the specific capacitance of the device,and finally realize the efficient construction of high energy density supercapacitor.Specific research contents are as follows:Firstly,nitrogen-doped porous carbon was prepared by high temperature pyrolysis and KOH activation using waste leather as precursor.The effects of preparation conditions on the structure and electrochemical properties of porous carbon were studied in detail.The characterization results show that the product has high nitrogen content,large specific surface area and abundant hierarchical porous structure.The porous carbon electrode has a maximum specific capacitance of 421 F/g at 1.0 A/g,and its electrochemical stability is significantly improved.Secondly,using the porous carbon material as the substrate,the consistency of its pyrrole nitrogen structure and pyrrole monomer was used to grow polypyrrole in situ.After carbonization again,the porous carbon/polypyrrole based composite carbon material with high nitrogen content of leather scrap was prepared.The specific capacitance of the composite electrode reaches 720 F/g at 1 m V/s.The solid supercapacitor assembled by the composite electrode material has a power density of 223.9 W/kg and an energy density of8.5 Wh/kg,showing a very high specific capacitance retention after 5000 electrochemical cycles.Finally,polypyrrole and Mo S₂ were loaded in situ on porous carbon matrix by chemical oxidation polymerization and solvothermal method respectively,and the two kinds of composites were assembled as positive and negative electrodes respectively to form asymmetric supercapacitors.The successful preparation of the two composites was confirmed by X-ray photoelectron spectroscopy(XPS).The assembled asymmetric supercapacitor showed excellent electrochemical performance,with a high specific capacitance value of 136.7 F/g at a sweep rate of 1 m V/s and an energy density of 20.1Wh/kg at a power density of 395 W/kg.