Ce-Doped Nanosheet as Visible Light Photocatalyst for the Photocatalytic Degradation of Tetracycline Hydrochloride

In this paper, a facile and efficient photocatalytic system for tetracycline hydrochloride (TCH) degradation is proposed. Ce-doped Bi2WO6 (Ce–Bi2WO6) nanosheets rich in oxygen vacancies were synthesized using a simple hydrothermal method and were systematically characterized. The results exhibited that a 10% Ce–Bi2WO6 (BWCe-10) catalyst with thinner and curling nanosheets was rich in oxygen vacancies, and the band gap was narrowed from 2.78 eV (Bi2WO6) to 1.61 eV, which was conducive to enhancing the photocatalytic activity of BWCe-10. As expected, BWCe-10 nanosheets exhibited much higher photocatalytic performance with 61.1% degradation of TCH within 40 min due to the formation of oxygen vacancies. Moreover, the addition of H2O2 further enhanced the TCH degradation efficiency and yielded a removal rate of 90.4%, revealing a strong synergistic effect between oxygen vacancies and H2O2 in the BWCe-10/H2O2/light system. As an electron acceptor, H2O2 boosts the separation rate of the photogenerated carriers, thereby improving the photocatalytic activity. Furthermore, the potential applications of the BWCe-10 nanosheet in terms of the effect of coexisting ions, stability, and universality were investigated. In addition, possible degradation mechanisms and pathways were proposed. In this system, h+ and e– played important roles in TCH degradation and followed the sequence h+/e– > •O2– > •OH, and the formation of •OH and •O2– was proved by ESR analysis. This simulated sunlight-driven system offers insights into the degradation of organic contaminants.