Photocatalytic degradation of malachite green by H3PW12O40/TiO2 under visible-light irradiation
H3PW12O40/TiO2可见光下光催化降解孔雀石绿的研究

A composite H3PW12O40/TiO2 photocatalyst was prepared by impregnating H3PW12O40 onto nanosized TiO2, which was prepared by a sol-gel method with tetrabutyl titanate. The composite photocatalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR) and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the catalyst toward decomposing malachite green (MG) was studied under visible-light irradiation. The influences of several operating parameters, such as impregnation volume, the dosage of catalyst, initial dye concentration, and pH, on the photocatalytic degradation of MG were investigated. The degradation rate of MG with H3PW12O40/TiO2 was 78% after being treated for 4 h under 300 W visible-light irradiation at pH 5, with 2 L·min-1 aeration using 0.3 g·L-1 H3PW12O40/TiO2 as the photocatalyst, which was higher than that when using TiO2 photocatalyst alone.