Preparation And Photocatalytic Properties Of Cu₂O-Oxide Composite Photocatalyst Thin Films

In this shudy, Cu2O-Oxide composite photocatalyst thin films were prepared by electrochemical deposition and Chemical method, then some typical wastewater and Organophosphate trichlorfon as the study object was leading research direction.X-ray diffraction(XRD), scanning electron microscopy(SEM),Raman scattering were used to analysis and testing the phase structure of composite films and the morphology of the surface which were prepar in different ways under different conditions.Systematically studied various process parameters on the structure and properties.The results sa follows:①A conventional two-electrode cell was used with an ITO substrate and a platinum as the working electrode, thin films of Cu2O were electrodeposited in copper sulfate and lactic acid, thin films of ZnO were electrodeposited in zinc nitrate and potassium nitrate, The morphological structure of the photocatalyst particles was characterized by XRD,SEM and so on. The result showed that the product was indeed Cu2O and ZnO which were preparated by electrochemical deposition, the morphology of Cu2O and ZnO particles were uniform cubic structure and hexagonal crystals respectively,successful synthesis of Cu2O-ZnO thin films at the same time. The pH value of electrolyte, current of electrochemical deposition and so on have influence on the Surface morphology of the films.②Preparation of the ZnO-Cu2O composite films by Sol-gel method, use slide as the carrier, preparation of Fe2O3-Cu2O, SnO2-Cu2O, SiO2-Cu2O composite thin film catalyst, the result showed that the product was indeed ZnO which were preparated by Sol-gel, and the morphology of ZnO particles was uniform structure of hexagonal zinc, Measured by SEM shows that ZnO thin films prepared at 400℃system have good crystallinity, distribution uniform, large specific surface area of particles,and there are flat and clear interface of Composite films. As the annealing temperature increases, ZnO grain size also increases.③Use electrochemical and chemical method respectively to preparation of composite photocatalytic films,then research the photocatalytic of degradation refractory materials for activity of dye solution. The results show that, preparation Cu20-Zn0 composite film by electrochemical have the best effect in photocatalytic, in the same time,10ml volume concentration of 25mg/1 of the activity red for the degradation rate is 99.7%.However ZnO-Cu2O composite film which was prepared by chemical method have the best effect of photochemical catalysis, in the same time,10ml volume concentration of 25mg/l of the activity red for the for the degradation rate is 99.7%. The single factor experiments showed that,the concentration was the most important factor on the photocatalytic activity,followed by the pH and the temperature.The optimum conditions of the Cu2O-ZnO thin film were:the concentration of electrolyte was 0.4M,pH was 7.88, temperature was 60℃, deposition current was 0.025A, deposition time was 30min. The single factor experiments showed that,the layers is the most important factor on the photocatalytic activity,followed by the lactic acid and the temperature.The optimum conditions of the ZnO- CU2O thin film were:zinc acetate:ethanol=1:85, lactic acid 6ml, five layers and calcination temperature was 400℃.④The Cu2O-ZnO and ZnO- Cu2O which were preparated by different methods and the different preparation conditions of the different method were used to decompose the trichlorfon. The degradation result of the compound membrane is superior to the simple membrane. The initial density is 60mg/l, illumination 10h, Removal rate to metrifonate COD respectively reach:electroplating Cu2O-ZnO was 91.2%, electroplating ZnO-Cu2O was 85.4%, Sol-gel ZnO-Cu2O was 88.7%, Sol-gel ZnO was 53.6%, electroplating Cu2O was 51.1%, This shows that Cu2O- ZnO compound photocatalyst degeneration dibaichong obtains the good effect, the degradation of trichlorfon in accordance with level dynamics law.