A novel (α/β-CdS)/Ce(OH)CO3 composite for enhanced photocatalytic degradation of high-concentration oxytetracycline at room temperature

This work reports the synthesis of a novel ( α / β- CdS)/Ce(OH)CO 3 composite featuring both heterojunction and heterogeneous junction structures via a simple injection titration-stirring method. The as-prepared composite exhibited excellent visible-light-driven photocatalytic activity for the degradation of high-concentration oxytetracycline (OTC) solution. Under optimal conditions determined by single-factor and response surface analyses, 0.0300 g of the composite achieved a 75.26% degradation efficiency for 50 mL of 160 mg/L OTC solution within 120 min of visible light irradiation. Notably, the composite demonstrated remarkable stability, retaining 62.39% of its initial activity after five cycles, and showed enhanced performance under real sunlight for 120 min, with a degradation rate of 78.50%. The improved photocatalytic performance is attributed to the uniform dispersion of CdS nanoparticles with abundant sulfur vacancies, which increase light absorption and facilitate charge carrier separation. Furthermore, the formation of direct Z -scheme heterojunctions and heterogeneous junctions between CdS and Ce(OH)CO 3 promotes efficient separation and transport of photogenerated carriers, thereby enhancing both photocatalytic activity and material stability.