| Supercapacitors are a medium for storing charges with higher power and energy densities than batteries and conventional electrochemical capacitors.However,the changes in the surface state,composition structure and basic properties of the electrode will significantly affect the interaction between the electrode and the electrolyte in the practical application process,so as to change the working efficiency of the supercapacitor and produce irreversible energy loss.Because the threedimensional network skeleton of copper foam provides sufficient transport channels for electrolyte diffusion and ion transfer,this topic research the preparation methods of copper-based nanometer composite electrode and its influence factors of the electrochemical properties with the copper foam as copper source and collector,clarity on the surface of the electrode material and charge transfer in the process of electrochemical behavior and structural evolution process of contact between the electrode and the electrolyte interface to the coupling mechanism of mass transfer and electrochemical reaction,to solve the problem existing in the working process of the composite electrode to inadequate mass transfer and structure of the common problems such as instability to provide theoretical basis and experimental basis.In this study,Cu（OH）2 nanowires and CuO nanosheets were prepared on the surface of copper foam by anodic oxidation and cyclic voltammetry respectively,and the effects of solution solubility,current size and deposition time on the surface morphology,crystal structure and chemical composition of the electrode surface were systematically studied.The results showed that Cu（OH）2 nanowires were used as the reaction precursor to form a dense crystal structure of CuO nanosheets through dissolution and reconstruction of its crystal structure.The area specific capacitance of the CuO/Cu electrode reached 2061 m F cm-2 at the scanning rate of 10 m V s-1,which was larger than the area specific capacitance of Cu（OH）2/Cu electrode under the same conditions.To solve the problems of conductivity and structural stability of the composite electrode,the composite electrode of copper oxide and graphene was prepared.Horizontal and vertically oriented graphene was prepared by solid carbon source metal catalysis and microwave plasma-enhanced chemical vapor deposition,respectively.It was found that vertically oriented graphene nanosheets（GNSs）were more conducive to ion diffusion and charge transfer.By anodic oxidation was prepared by in situ CuO-Cu2O@GNS/Cu composite electrode,when the scan rate is 10 m V s-1,specific capacitance values of electrode reached 243 m F cm-2,equivalent series resistance of 0.69 Ω,and the specific capacitance of electrode increased by 20% after 5000 times continuous charging and discharging,showed excellent cycle stability with higher energy density and power density compared with the electric double-layer capacitor.Porous carbon nano-onions structures with superhydrophobic properties were prepared by microwave plasma enhanced chemical vapor deposition,and realized the transfer of superhydrophobic property to the electrode surfaces.In order to study the coupling mechanism of electrode wettability and electrochemical reaction,a superhydrophobic carbon nano-onion coating was deposited to copper foil,and the mechanism of material and charge transfer in electrochemical reaction system was discussed.It is concluded that Wenzel-Cassie coexisting state plays an important role in promoting the anodized deposition of Cu（OH）2 nanostructures and significantly increasing the nucleation density of Cu（OH）2 nanoparticles.Therefore,by reasonably designing the wetting property of the composite electrode surface,the composition of the three-phase contact boundary is controlled,which provides a theoretical basis for overcoming the problem of insufficient gas in the underwater gas-consuming reaction system and designing efficient electrode. |
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