Construction of the CeTiOx-CdS redox system: Effect of Cr(Ⅵ) concentration on photocatalytic degradation organic pollutants in water

By combining the sol-gel method with the coprecipitation synthesis strategy, a series of cadmium sulfide-based catalysts (MTiO x -CdS, where M = Ce, Co, Cu, Zn) were successfully prepared. Under simulated sunlight irradiation, the material exhibited efficient and stable degradation performance for ciprofloxacin (CIP). Remarkably, by constructing a Cr(Ⅵ)-mediated redox system, a significant leap in degradation efficiency from nearly zero to 90% was achieved for bisphenol A (BPA) and ibuprofen (IBU). Studies reveal that Cr(Ⅵ) plays a dual role in this system, acting as both an "electron bridge" and an "adsorption anchor": on one hand, it serves as an electron acceptor to significantly inhibit charge carrier recombination; on the other hand, it enriches pollutants through coordination effects, thereby synergistically enhancing electron transfer and interfacial reactions. This work not only presents a cost-effective and efficient strategy for the synthesis of MTiO x -CdS photocatalysts but also offers valuable insights into the development of novel photocatalytic systems aimed at the remediation of complex water pollution and energy conversion applications.