Heterogeneous Photocatalytic Mineralization of Chlorobenzene by Paratungstate-loaded Titania Catalysts in an Aqueous Medium

摘要

Paratungstate-loaded titania catalysts were prepared via the addition of a series of aqueous solutions of paratung-state(denoted as W_7)into an isopropanol solution of Ti[OCH(CH_3)_2]_4 by means of the sol-gel method.The catalysts were characterized by EDX,BET,FTIR,UV-Vis DRS,XRD and the results indicate that such paratungstate-loaded catalysts maintained their heptatungstate structure in the anatase titania matrix up to 400 degC.The catalysts were tested for the heterogeneous photodegradation of chlorobenzene in aqueous media and showed a better catalytic activity than P-25 TiO_2 because paratungstate can prevent the recombination of the holes and electrons produced during irradiation.Moreover,the paratungstate-loaded titania catalysts can resist the disaggregation during the photoirra-diation and can be easily recycled from the aqueous suspensions after reactions.