Experimental Study On The Photocatalytic Property Of ZnO-TiO₂

Nanometer ZnO and TiO₂in photocatalytic materials have good optical performance,stablechemical properties，advantages of non-toxic and no secondary pollution, etc. But the absorptionwavelength range is narrow and utilization rate of the sun is low, Nanometer ZnO and TiO₂modified photocatalytic materials have the combination of the advantages of ZnO and TiO₂, sophotocatalytic materials ZnO-TiO₂is becoming a hot spot of environmental governance research.The performance of ZnO-TiO₂photocatalytic degradation on wastewater was analyzedexperimentally in this study.ZnO-TiO₂photocatalytic powders were prepared by means of so1-gel, The photocatalyticactivities were evaluated by degradation of pharmaceutical wastewater and dye wastewater,Analysed with orthogonal experiments and single factor experiments,the primary and secondaryorder of ZnO-TiO₂powders，photocatalytic degradation effects was determined as follow:calcination time, calcination temperature, ZnO，S doping ratio, irradiation time. The ZnO-TiO₂were characterized by means of XRD, HRTEM, TG-DSC, Raman and UV-Vis. The resultsshowed that ZnO doped was conducive to the shift of the TiO₂lattice toward the anatase phase,the particle size was reduced for the expansion of TiO₂optical absorption response range andthe efficiency of TiO₂photocatalysis was also improved. The best preparation conditions:calcination temperature is600℃, calcination timeis1.5h, ZnO doping quantity is5%,illumination time is2h, the Chroma removal rate of ZnO-TiO₂modified photocatalyticmaterials prepared under this condition for pharmaceutical wastewater was48.0%, while theCOD removal rate was82.3%; the decolorization rate methyl orange and acid red B dyewastewater can reach60%.