Studies On The Synthesis Of Carbon Cloth-based Transition Metal Compounds Self-supporting Electrodes And Their Electrochemical Properties

The development of hydrogen and the application of energy storage equipments can effectively alleviate the problems of environmental pollution and energy crisis.Electrolytic water is one of the most promising hydrogen production methods,while supercapacitors and lithium ion batteries play an important role in energy storage.Electrode materials greatly affect the efficiency of hydrogen production by water electrolysis and the reliability of energy storage devices.The ideal catalyst should have the advantages of excellent catalytic activity and good long-term stability,as well as high theoretical capacity for lithium-ion battery electrode materials.The development of low-cost and efficient non-precious metal catalysts is the key to improving the performance of hydrogen production by water electrolysis,supercapacitors and lithium ion batteries.However,traditional electrode materials rely on organic binders,and the active material is easily dropped from the substrate under high current density or long-term operation,resulting in poor cycle stability.The self-supporting electrode concept proposed in recent years can solve this problem well.In this paper,a simple hydrothermal method combined with high-temperature calcination is used to load the active material on a 3D flexible substrate（carbon cloth）to prepare a self-supporting electrode and explore its electrocatalytic and energy storage performance.The following are the conclusions of the study:（1）Firstly,the carbon cloth was thermally reduced and etched to prepare the CFC@EC with excellent oxygen evolution reaction（OER）performance.Then,CFC@EC/NiFe-LDH catalyst is successfully prepared by hydrothermal method using it as a substrate,and explore the electrochemical performance of the electrode.The extremely low overpotential and Tafel slope of CFC@EC/NiFe-LDH indicate that the electrode has superior catalytic activity and reaction kinetics compared with CFC/NiFe-LDH.To demonstrate the applicability of CFC@EC as an OER catalytic electrode substrate,we also explore the catalytic performance of CFC@EC/NiCo-LDH and CFC@EC/NiMn-LDH electrodes,respectively.The LSV curves,Tafel slope and EIS plots all indicate that the OER performance of these two electrodes have sufficient advantages compared with the comparative electrode.This strategy of using CFC@EC as an electrocatalyst substrate provides a new idea for the development of other electrocatalysts.（2）In order to improve the efficiency of electrolytic water,the hydrogen evolution reaction（HER）catalyst with the same excellent performance are developed.Using Co P as the active material,CFC@EC/Co P with a core-double shell structure is prepared by a hydrothermal method.The results of Tafel and EIS show that the HER kinetics and conductivity of CFC@EC/Co P are significantly better than those of CFC/Co P.In addition,we investigate the hydrogen evolution catalytic activities of CFC@EC/Ni₃S₂and CFC@EC/Co S₂ catalysts,and the results show that CFC@EC-based catalysts also have certain advantages in hydrogen evolution reaction.Meanwhile,the overall water splitting device of CFC@EC/NiFe-LDH//CFC@EC/Co P has a potential of 1.53 V at 10m A cm^-2 and exhibits good reaction kinetics.The self-supporting electrode prepared in this work possesses a unique core-double shell structure,which is expected to be practically applied in the field of electrocatalytic water splitting,and also lays a foundation for improving the application of CFC@EC in other fields.（3）Using carbon cloth as the conductive substrate,CC/MoO₂/MoS₂ and CC/Mo₂C/MoN/MoS₂ electrodes are synthesized by seed-assisted hydrothermal method and calcined in different atmospheres,and investigated their lithium storage performance as anode materials for lithium ion batteries.The electrochemical active surface area test results of CC/MoO₂-α/MoS₂-10 and CC/Mo₂C/MoN-α/MoS₂-10（α=1,2,3,4）show that the optimum calcination time for MoO₂ and Mo₂C/MoN is 2 h and 3h.Then,we explore the effect of loading different thicknesses of MoS₂ on the precursor on the lithium storage capacity of the composite electrode was explored.Since MoO₂and Mo₂C/MoN can effectively improve the severe stacking of MoS₂,and the interaction between the precursor and MoS₂ is conducive to ion diffusion and electron transport ability,it can effectively improve the area capacity,rate performance and electrical conductivity of the material.Therefore,CC/MoO₂-2/MoS₂-10 and CC/Mo₂C/MoN-3/MoS₂-10 have the best lithium storage capacity.