Photocatalytic degradation of organic dyes under solar light irradiation combined with Er3+:YAlO3/Fe- and Co-doped TiO2 coated composites

In order to extend the photocatalytic performance of TiO2, two new photocatalysts of Er3+:YAlO3/Fe- and Co-doped TiO2 coated composites were prepared by the sol-gel process and characterized by XRD and TG-DTA, And then, their photocatalytic activities through the degradation of azo fuchsine under solar light irradiation were evaluated by HPLC techniques and UV-vis spectra. The influencing factors such as the Er3+:YAlO3 content, heat-treated temperature and heat-treated time on the photocatalytic activities of Er3+:YAlO3/Fe- and Co-doped TiO2 coated composites were reviewed. Otherwise, the solar light irradiation time, initial concentration of azo fuchsine, photocatalyst addition amount and kind of organic dyes on the photocatalytic degradation of azo fuchsine were also studied. All experimental results indicate that the Er3+:YAlO3/Fe- and Co-doped TiO2 coated composites are more effective than Fe- and Co-doped TiO2 powders. That is because the Er3+:YAlO3 can transform the visible light into the ultraviolet light and enhance the photocatalytic activities of Fe- and Co-doped TiO2 powders. It is possible to provide a new way to utilize the Er3+:YAlO3/Fe- and Co-doped TiO2 coated composites under the solar light irradiation for the treatment of wastewater in the future. (C) 2010 Elsevier B.V. All rights reserved.