Enhancement of photocatalytic activity on salicylic acid by nonmetal-doped TiO2 with solvothermal method

Abstract

Nonmetal-doped TiO2 nanoparticles have been prepared by the solvothermal method. The as-prepared photocatalysts have been characterized by X-ray diffraction, UV–vis diffuse reflectance spectra, Scanning electron microscope, Transmission electron microscopy, Specific surface area (BET) and X-ray photoelectron spectroscopy. The results indicate different atom radius and valence of the N, S and B atoms that cause the different doping ways, and it could form different lattice, which led to different surface area and pore volume of as-prepared photocatalysts. It is confirmed that S as S6+ incorporate into the crystal lattice of the S–TiO2, which may be the O–S–O–Ti–O linkages in the crystal lattice. It may be N and S as Ti–N–O or Ti–N–O2 and S2− in the crystal lattice of the N&S co-doped TiO2, respectively, which may be the S–Ti–N–O linkages in the crystal lattice. Photocatalytic activity was studied by degradation of salicylic acid under visible light. The degradation rate of salicylic acid reached 76.25% with N&S co-doped TiO2 photocatalyst in 120 min, which is the highest of all the as-prepared photocatalysts. Furthermore, the experimental data of photocatalytic degradation well followed the Langmuir–Hinshelwood kinetics.