A Novel Approach Towards High-performance Composite Photocatalyst Of Tio_2 Deposited On Activated Carbon

摘要

TiO_2 photocatalysts deposited on activated carbon (TiO_2/AC) were prepared by dip-hydrothermal method at 180 ℃ using peroxotitanate as a precursor, then calcinated at 300-800 ℃. The samples were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy and the nitrogen absorption. Their photocatalytic activity was evaluated by degradation of methyl orange (MO). The results showed that TiO_2 particles of anatase type were well deposited on the activated carbon surface. TiO_2/AC calcinated at 600 ℃ exhibited the best photocatalytic performance. For the comparison, the same photocatalysis experiment was carried out for two mixtures of commercial TiO_2 (Degussa P25) with AC and synthetic TiO_2 with AC. It was found that the composite catalyst TiO_2/AC was better than the two mixtures. Besides, different from fine powdered TiO_2, the granular TiO_2/AC photocatalysts could be easily separated from the bulk solution and reused; indeed, its photocatalytic ability was hardly decreased after a five-cycle for MO degradation. The kinetics of the MO degradation fitted well the Langmuir-Hinshelwood model.