Synthesis Of Transition Metal Based Carbon Materials For Electrochemical Properties

Environmental pollution control and new energy development and utilization are the two primary tasks that need to be completed to achieve a sustainable development strategy.Organic matter is an important source of environmental pollution,especially water pollution.Most of the organic matter has a stable structure,which is difficult to degrade under natural ecological conditions and seriously harms the human living environment.In addition,hydrogen energy is clean,efficient and renewable,and it is a promising new energy source,and electrocatalytic decomposition of water is an important method for large-scale production of hydrogen.Based on the above reasons,this thesis synthesized a multifunctional electrode material,which has excellent electrocatalytic performance.It can not only catalyze the activation of persulfate through organic assisted methods to efficiently degrade organic pollutants,but also can be used as an efficient working electrode for hydrogen evolution reaction,oxygen evolution reaction and overall water splitting.So,it has good application prospects in the environment and energy fields.The details are as follows:（1）A two-step electrodeposition method was used to prepare a polypyrrole-coated cobalt composite on a carbon cloth substrate（CC）,which was then carbonized under high temperature nitrogen to obtain a CC-supported cobalt-carbon self-supporting electrode material（Co@NC/CC）.Through characterization,the material presents a network structure of cobalt nanoparticles coated with nitrogen-doped carbon,which can effectively solve the problem of secondary pollution caused by metal overflow during the use of the catalyst.In addition,its superior conductivity greatly promotes the electrocatalytic process.（2）Using the above Co@NC/CC self-supporting material as a working electrode,construct a three-electrode electrocatalytic system.Common phenol was selected as the model pollutant and persulfate was used as the oxidant to explore the catalytic oxidation performance under electro-assisted catalytic conditions.The experiment found that the self-supporting material itself has good chemical catalytic activity to PMS and can completely degrade 20 ppm phenol in 40 min.Through electro-assisted catalysis,its catalytic capacity is further strengthened,and the time required for degradation suddenly drops to 6 min.In addition,in this paper,the use of free radical quenching reaction,in-depth study of the role of electrocatalysis in this process,found that electric assisted by promoting the free radical reaction process to improve its pollutant degradation activity.（3）Taking Co@NC/CC self-supporting material as the working electrode,this paper also studied its electrocatalytic activity in hydrogen evolution reaction,oxygen evolution reaction and total hydrolysis.The results show that the material exhibits high activity in electrocatalytic water decomposition,especially under alkaline conditions when Co@NC/CC reaches a hydrogen evolution current of 10 m A cm^-2,its hydrogen evolution overpotential can be as low as-118 m V.In the preparation process of the above electrodes,the preparation of cobalt-carbon precursors by electrodeposition helps to form a tight interface structure,thereby accelerating charge transfer and enhancing its catalytic activity.In addition,the presence of the carbon layer can also protect the internal metal and prevent water pollution caused by dissolution during the catalytic process.The material does not contain precious metals and has low cost.It has good application prospects in the environment and energy fields.