Influence of Sol-Gel and Dip-Hydrothermal Preparation Methods on Structure and Performance of TiO2/AC Photocatalysts

TiO2, catalysts deposited on activated carbon (TiO2/AC) were prepared by sol-gel and dip-hydrothermal methods to investigate the effect of preparation methods on the structure and catalytic performance of TiO2/AC catalysts. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and nitrogen adsorption. Results show that the TiO2, produced by the sol-gel method consists of irregular fragments coated onto the carbon surface and that the dip-hydrothermal method leads to nanorods being deposited onto the AC surface. The mesoporous and microporous specific surface areas of the TiO2/AC samples prepared by the diphydrothermal method were larger than those of the sol-gel samples, and the diameters of the TiO2 particles prepared by the former method were smaller. The performance of the TiO2/AC composite photocatalysts was evaluated by the degradation of methyl orange (MO). We found that 600 degrees C was the optimal temperature for the calcination of TiO2. Furthermore, the photocatalytic activities of TiO2/AC samples prepared by the dip-hydrothermal method were obviously better than those prepared by the sol-gel method.