Bi2Sn2O7-TiO2 nanocomposites for enhancing visible light photocatalytic activity

Bi2Sn2O7-TiO2 nanocomposites with different ratios of Bi2Sn2O7 (BSO) and TiO2 were prepared by combining a facile co-precipitation method with the aid of a template. X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy were employed to characterize the physicochemical properties of the as-prepared nanocomposites. The band gap energies of the nanocomposites were established by diffuse reflectance UV-Vis spectra. The specific surface area and average pore diameter of the nanoparticles were measured by an N-2 adsorption-desorption isotherm. Photocatalytic degradation of Rhodamine B dye molecules was also investigated in the visible region so as to explore the photocatalytic activity of the as-prepared nanocomposites. The results showed that the 10BSO-TiO2 nanocomposites had a remarkably enhanced photocatalytic performance as compared with other samples including anatase TiO2. It was also found that all BSO modified TiO2 samples had a wider band gap energy than the pure BSO sample, but showed a higher photocatalytic activity than the pure BSO sample due to the photosensitization mechanism of the dye molecules.