Photocatalytic degradation of MO by complex nanometer particles WO3/TiO2

Complex nanometer particles WO3/TiO2 were prepared using a sol-gel process and characterized using XRD spectra. The photocatalytic activity of TiO2 can be increased by doping W6+ with TiO2 because the doped W6+ that entered into the crystal lattices of TiO2 led to the formation of defects in the crystal lattices of TiO2 and thereby improved the photocatalytic activity of TiO2. When WO3 doped in TiO2 exceeded 3%, the excess W6+ did not enter into the crystal lattices of TiO2 but were uniformly dispersed in TiO2 or they covered the surface of TiO2, which reduced the effective illumination area of TiO2 and thereby lowered the photocatalytic activity of TiO2. The relationship among the composition of the catalyst, the amount of photocatalyst, the illumination time, and the decolorizing rate of methyl orange (MO) were discussed. The results show that the decolorizing rate of MO can reach 82.3% using WO3TiO2 as the photocatalyst, with the composition of WO3/TiO2 = 3:97, the mass of catalyst = 0.400 g, the initial concentration of MO = 20 mg/L, pH = 6.5, and the illumination time = 7 h.