Abstract:

In order to expand the practical application of photocatalysis and meet the increasingly stringent environmental requirements, weak UV light-driven TiO2 composite photocatalysts with high performance were prepared by adsorption phase synthesis. Transmission electron microscopy, high resolution transmission electron imcroscopy and X-ray diffraction were employed to characterize the morphology of different catalysts. Combining the results by photoluminescence spectra with the degradation of methyl-orange excited by weak UV light, the influence of the catalyst structure on the recombination of photogenerated carriers and its photocatalytic activity was expolred. The results indicate that Ce3+ doping with low doping content (less than 0.10%) leads to the lattice expansion of TiO2 and introduced some shallow capture sites for photogenerated carriers, thus enhancing the activity of the catalyst. At high doping content (≥ 0.20%), Ce3+ doping greatly inhibites the crystallization of TiO2 and caused a large amount of amorphous TiO2 in the catalysts, which significantly depressed the photocatalytic activity illuminated under weak UV light. The higher the calcination temperature is, the more obvious the effect of Ce3+ doping on the structure and activity of the catalysts is. For photodegradation for methyl-orange with high concentration, the degradation efficiency of the optimum catalyst is two times higher than that of the commercial photocatalyst P25.

Key words: adsorption phase synthesis, cerium ions doping, photocatalysis, composite photocatalyst, efficient degradation of methyl-orange