Ce-Doped Brookite TiO2 Quasi-Nanocubes for Efficient Visible Light Catalytic Degradation of Tetracycline

Tetracycline (TC) is one of the most produced and used antibiotics in the world. The accumulation and migration of TC in water bodies cause serious environmental pollution and biological health problems. In this study, three kinds of brookite TiO2 (Ce/BTN) nanophotocatalysts with different Ce doping amounts were synthesized by a one-pot hydrothermal method, which provided an effective way to solve this problem. The chemical and photoelectric properties of nanomaterials were measured by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and photoelectrochemical techniques. The results show that after Ce doping, the sample still maintains the brookite crystal form with high crystallinity, and the morphology does not change significantly. However, the impurity energy level can be formed after Ce doping in the brookite TiO2, which reduces the band gap and extends the range of spectral response. The photocatalytic activity of different catalysts was evaluated by degrading TC solutions under simulated visible light. Based on the free radical capture experiment, the effective active species of the catalyst to degrade tetracycline was determined, and the mechanism of photocatalyst degradation was proposed.