Photocatalytic degradation of methylene blue using immobilized nano-particles of TiO_2 supported by SBA-15 surface

摘要

TiO_2-SBA-15 surface (TSS) composites were prepared by the supercritical pretreatment and then sol-gel process with using paraffin used as a clogging agent. The as-grown materials were characterized by using X-ray diffraction, UV-VIS spectroscopy and nitrogen absorption. The photocatalytic activities of TSS were evaluated by quantifying the degradation of methylene blue solution under UV light. Compared with Ti02-SBA-15 (TS) composites prepared only by the sol-gel method, TSS composites remain in mesostructure with high surface areas due to clogging effect of paraffin on SBA-15 cavity. Additionally, the small crystalline size of TiO_2 in TSS is attributed to the fact that silica support baffles the agglomeration of TiO_2 nanoparticles. In comparison of TS composites and pure TiO_2, higher photocatalytic activity of TSS is obtained and mainly attributed to larger surface areas and greater band-gap energy.