CeO2/BiYO3 photocatalyst for the degradation of tetracycline under visible light irradiation

Photocatalysis has received extensive attention as a promising method for reducing antibiotic contamination in water. In this study, we prepared and investigated the photodegradation efficiency of the CeO₂/BiYO₃ system, using tetracycline (TC) as a model pollutant. The composites demonstrated significantly higher photocatalytic activity compared to pure BiYO₃ and CeO₂, demonstrating their potential as effective photocatalysts. A detailed investigation of the band potentials indicated that the two semiconductors form a type II heterojunction, enhancing charge separation. Furthermore, the presence of the Ce³⁺/Ce⁴⁺ redox couple serves as an electron trap site, improving the photocatalytic performance by reducing electron-hole recombination. The catalyst achieved peak efficiency only during the first cycle. However, a simple annealing process effectively regenerated the catalyst to its original efficiency, suggesting that the CeO₂/BiYO₃ composite can be reused with minimal loss of activity. Additionally, we examined the distinct photodegradation mechanisms of pure BiYO₃ and the CeO₂/BiYO₃ composite. Our results provide insights into how the formation of heterostructures influences photocatalytic processes. These findings are valuable for the future design and development of related heterostructure photocatalysts, aiming to enhance their efficiency for the degradation of various pollutants.