| Abstract:In this paper, highly efficient and stable visible light photocatalytsts were fabricated through modified the spinel structure of MAl2O4(M=Cu,Zn).Firstly, Zn-doped CuO/CuAl2O4and ZnO/CuO/ZnAl2O4composite hollow spheres were synthesized by hydrothermal method, using glucose as template, PEG-4000as dispersants and Zn(NO3)2·6H2O, Cu(NO3)2·3H2O, Al(NO3)3·9H2O as main raw materials. The samples were characterized by XRD, SEM, HRTEM, BET, IR, TG/DTA, UV-Vis DRS and PL spectra. The photocatalytic activities of the samples were investigated by measuring the decororization of methyl orange (MO) under simulated sunlight irradiation.Secondly, Zn-doped CuO/CuAl2O4composite photocatalysts prepared by hydrothermal-template method, presented hollow spheres shape with specific surface area up to214.97m2·g-1and the diameter is about2μm. The results showed that Zn doped photocatalysts exhibited enhanced the ultraviolet and visible absorption ability of CuO/CuAl2O4and decreased electron-hole recombination. The photocatalytic activities of the samples were greatly increased. The influences of pH, Zn doping content, calcination temperature and photocatalyst dosage on photocatalytic activities were investigated. The highest photocatalytic efficiency was obtained when the samples were prepared at pH8, Zn doping content was0.5wt%, calcination temperature was600℃and the photocatalyst dosage was0.5g/L. After irradiated for60min, the decolorizing efficiency of100mg·L-1MO was as high as97%, and the photocatalytic H2evolution rate was2.34mmol·h-1·g-1.Finally, ZnO/CuO/ZnAl2O4composite photocatalysts which prepared by one-step hydrothermal method, presented hollow spheres structure. The effects of pH value, calcination temperature, PEG dosage and Zn/Cu molar ratio on photocatalytic activities were investigated. The results showed that the best photocatalytic performance was obtained when the samples were synthesized at pH7, PEG amount was5%, and Zn/Cu molar ratio was1:1. The samples which calcined at500℃were own strong adsorption ability with biggest specific surface area. Further more, the research also showed that combined with CuO was benefit to improve the ultraviolet and visible light absorption performance of ZnO/ZnAl2O4samples, make the absorption edge red shift from450nm to900nm. |
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