Preparation And Electrochemical Properties Of CuO Nanostructure On Copper Matrix

Copper oxide（CuO）, as a very important transition metal oxides, has many functionalapplications, especially in electrochemical aspects. Such as, it can be used for electricity catalystof Fuel cells and can be used as electrode materials for surpercapacitor and Lithium ion battery.In the present dissertation, CuO nanowires, nanosheets, and flower-like nanostructure weresynthesized on copper foam and/or copper foil via different methods. The electrode wascharacterized by X-rays diffraction （XRD） and scanning electron microscopy （SEM）. Theelectrochemical performance was investigated by some electro chemical mearuring technologys,such as Cyclic voltammetry （CV） and Electrochemical impedance spectro-scopic （EIS）.CuO nanowires electrode（A and B） were manufactured through different methods, It wasfound that: The capacitance of CuO/Cu mainly was Faraday Pseudo-capacitance which wasproduced by the redox reaction of CuO．The electrode of A had a largest capacitance of92.28F·g^-1．With the increase of current density, the capacitance of the electrode declined, When thecurrent density was2.46mA mg^-1, the capacitance was71.68F·g^-1. The electrode of B had alargest capacitance of195F·g^-1．With the increase of current density, the capacitance of theelectrode declined, When current density was2.46mA mg^-1, the capacitance was104.5F·g^-1. Thespecific capacitance of CuO can be attributed to its difference in morphology. The electrode of Bhas a high volumetric spicific surface area and thus has smaller electrical resistance and largerspecific capacitance than that of A.CuO nanosheets electrode were manufactured through different methods, One of the CuO（the electrode of flower-like）nanosheet form clusters and cover the copper surface completelyand compactly, another one of the CuO （the electrode of nanosheets）presents as nanosheetsroughly aligned perpendicular to the copper surface completely and compactly. It was found that:The capacitance of CuO/Cu mainly was Faraday Pseudo-capacitance which was produced bythe redox reaction of CuO．The electrode of flower-like had a largest capacitance of142F·g^-1．With the increase of the current density, the capacitance of the electrode declined, Whenthe current density was2.46mA mg^-1, the capacitance was111F·g^-1. The electrode ofnanosheets had a largest capacitance of212F·g^-1．With the increase of current density, thecapacitance of the electrode declined, When the current density was2.46mA mg^-1, thecapacitance was141F·g^-1. The specific capacitance of CuO can be attributed to its difference inmorphology. The electrode of nanosheets has higher Specific surface which can enhance its utilization via reducing electrical resistance and increasing electrolyte diffusion within itsnanostructure, and thus has larger specific capacitance.As part of our ongoing research of low-cost electrocatalysts for H₂O₂based fuel cell, thepreparation and catalytic performance of CuO nanosheets freely standing on Cu foil for H₂O₂electroreduction was researched. The electrochemically active CuO nanosheets were grown fromthe Cu foil substrate in a single step, and the Cu foil served as both the substrate of CuOnanosheets and the current collector of the electrode. The results shows that: When hydrogenperoxide concentration was0.5mol·dm^-3, NaOH Electrolyte was3mol·dm^-3, the highest of thecurrent density is7.8mA mg^-1, the electrode exhibited high activity and good stability forelectrocatalytic reduction of H₂O₂.