Graphene modified Nd/TiO_2 photocatalyst for methyl orange degradation under visible light irradiation

摘要

A novel nanoscale GR-Nd/TiO_2 composite photocatalyst was synthesized by the hydrothermal method. Its crystal structure, surface morphology, chemical composition and optical properties were studied using XRD, TEM, and XPS, DRS and PL spectroscopy. It was found that graphene and neodymium modification shifts the absorption edge of TiO_2 to visible-light region. The results of photoluminescence (PL) emission spectra show that GR-Nd/TiO_2 composites possess better charge separation capability than do Nd/TiO_2 and pure TiO_2. The photocatalytic activity of prepared samples was investigated by degradation of methyl orange (MO) dye under visible light irradiation. The results show that the GR-Nd/TiO_2 composite can effectively photodegrade MO, showing an impressive photocatalytic activity enhancement over that of pure TiO_2. The enhanced photocatalytic activity of the composite catalyst might be attributed to the large adsorptivity of dyes, extended light absorption range and efficient charge separation due to Nd doping and graphene incorporation.