Preparation and photocatalytic application of terbium and sulfur co-doped titanium nanomaterials

Titanium-based nanomaterials co-doped with terbium (Tb) and sulfur (S) were synthesized by sol-gel method via a facile step. Physicochemical properties of the resulting composites were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), X-ray photo-electron spectroscopy (XPS) and UV-Vis diffused reflectance spectroscopy (DRS). Methylene blue (MB) was used as a degradation target for evaluating the photocatalytic performance. The factors which influence the photocatalytic activity were investigated, including calcined temperatures and S doping amount. Tb, S (2 wt%) co-doped TiO₂ composite calcined at 500 °C exhibited the highest photocatalytic activity with a degradation rate of 72.4% in 3 h. The reaction constant was 0.11529, 0.26025, 0.35038 and 0.41462 h^-1 for undoped TiO₂, Tb-doped TiO₂, S-doped TiO₂ and Tb, S co-doped TiO₂, respectively. Importantly, the synergistic effect of terbium and sulfur dopants was profoundly discussed. Furthermore, recycling tests and acute toxicity experiments were carried out to confirm the reusability and biosafety of Tb, S co-doped TiO₂.