Anchoring cubic CeO2 on the CdS surface to construct a heterojunction enables highly efficient visible-light photocatalytic degradation of tetracycline.

Developing stable, efficient, and pollution-free photocatalytic systems is crucial for enhancing the potentiality of photocatalytic materials in treating actual wastewater. In this study, a low-cost CeO2/CdS heterojunction catalyst was prepared, and its performance in degrading tetracycline hydrochloride (TC) was evaluated under 18 W LED illumination. XRD, FTIR, and HRTEM analyses confirmed that cubic CeO2 had been successfully anchored onto the CdS surface, forming a type II heterojunction. XPS and photoelectrochemical measurements indicated that CeO2 served as the electron relay station, facilitating the directed migration of photo-generated carriers from CdS to CeO2, thereby significantly enhancing the efficacy of photo-generated separation. Under simulated sunlight, the TC degradation rate of CeO2/CdS achieved 96.5%, which greatly exceeded that of pure CdS (9.9%) and CeO2 (7.1%), and CeO2/CdS exhibited excellent cycling stability. Furthermore, CeO2/CdS demonstrated highly efficient degradation of ofloxacin (OFL). Based on a comprehensive analysis of LC-MS, ESR, and free radical trapping experiments, the possible degradation pathways of TC had been elucidated. This study provides new insights into the design of highly efficient photocatalytic materials for wastewater treatment.