Effect of preparation methods on the structure and catalytic performance of TiO(2)/AC photocatalysts

Activated carbon (AC)-supported TiO(2) catalysts were prepared by sol-gel and metal organic chemical vapor deposition (MOCVD) in order to investigate effect of preparation methods on the structure and catalytic performance of TiO(2)/AC catalysts. It was found that both methods yield "egg-shell" TiO(2)/AC catalysts, that is to say, the TiO(2) coatings were mainly on the surface of AC supports. The TiO(2) coating by sol-gel was only coated on the external surface of AC. In contrast, TiO(2) by MOCVD was deposited on the surface of AC through the heterogeneous reaction, forming a TiO(2)+AC hybrid film (about 3 microm) as evidenced by SEM and N(2) adsorption tests. The hybrid TiO(2)+AC film could capture the intermediates produced during the degradation of the target pollutant resulting in efficient mineralization. The TiO(2)/AC catalysts by MOCVD exhibited a Ti-O-C bond, which correlated with the good stability of TiO(2) as observed on the corresponding samples. These results indicate MOCVD is a better choice for the preparation of TiO(2)/AC catalysts.