Preparation And Properties Of Copper-based Films By Electrodeposition

Supercapacitors have the advantages of high power density and long service life,which are widely used in the field of energy storage and conversion.Fenton oxidation is an advanced catalytic oxidation technology that is widely used in the deep purification of industrial wastewater.Copper metal has excellent conductivity and chemical stability,which is cheap and rich in resources.In addition,copper and its oxides can be used as both Fenton-like catalysts and important pseudocapacitor materials.In this thesis,copper-based thin films were prepared by electrochemical deposition and in-situ thermal oxidation method,which were used as electrodes for supercapacitors and electrochemical oxidation systems.Their morphology,structure and elemental composition were characterized.And the capacitance and electrochemical oxidation properties of the electrodes were studied.1.The Cu₂O/Cu porous granular film electrode was prepared by a combination of constant current electrochemical deposition and thermal oxidation.Triethanolamine was used as a surfactant during electrodeposition.The effects of the amount of triethanolamine,deposition current,deposition time,calcination temperature and operating voltage window on the electrochemical performance of the electrode were investigated,and the reasons of these effects were also discussed.The optimized sample showed good reversible pseudocapacitance performance in 1 M KOH solution under the potential window of-1～-0.2 V.When the scanning speed was 5 m V/s,its area capacitance can reach 158.8 m F/cm²;and at a current density of 9 m A/cm²,after 3000 cycles of charge and discharge,the capacitance retention of the electrode was 85.9%.2.The Cu₂O-NiO/CuNi porous granular film electrode was prepared by a combination of copper-nickel co-deposition and thermal oxidation.The effects of the copper-nickel ion ratio,the addition of triethanolamine,deposition current,deposition time and calcination temperature on the electrochemical performance of the electrode were studied,and the reasons of these effects were also discussed.When the scanning speed was 5 m V/s,the area capacitance of the optimized sample can reach 133.8 m F/cm² in 1 M KOH solution under a voltage window of-1～-0.2 V;and at a current density of 9 m A/cm²,the capacitance retention of the electrode after 3000 cycles was 87.8%.3.Porous Cu granular film was prepared by one-step constant current electrochemical deposition method,which was used as a cathode for an electrochemical oxidation system,and methyl orange was degraded under the conditions of no oxygen exposure and no additional catalyst.The effects of the amount of triethanolamine,p H value,degradation current,degradation time and degradation temperature on the electrochemical oxidation performance of the electrode were studied and the related reasons were discussed.Besides,the kinetics of electrochemical oxidation of methyl orange was preliminary investigated.The electro-oxidation of methyl orange belongs to the first-order reaction.Under normal temperature conditions,using porous Cu granular film cathode,the decolorization speed of the methyl orange solution was increased by about 70.9%compared with using carbon cathode.And the electrode has good reusability.