Kaolinite-Supported BiOCl_xBr_(1-x) Solid Solution Nanocomposites for Efficient Photocatalytic Removal of Organic Pollutants

Novel photocatalysts based on kaolinite-supported BiOCl_xBr_(1-x) solid solution nanocomposites (denoted as BiOCl_xBr_(1-x)@Kaol) were successfully synthesized using an eco-friendly co-precipitation method. These nanocomposites were designed for the enhanced removal of organic pollutants from contaminated water. Their photocatalytic performance was evaluated by degrading Rhodamine B (RhB) dye and Ciprofloxacin (CIP) antibiotic under visible light irradiation. Remarkable removal efficiencies were achieved, with 100% degradation of RhB within 15 minutes and 95% of CIP within 45 minutes. Furthermore, the reusability of the photocatalysts was tested over five consecutive cycles, during which the performance remained stable. This indicates that kaolinite not only acts as a support but also plays a critical role in enhancing the structural stability and durability of the photocatalyst. To better understand the interaction mechanisms, Monte Carlo simulations based on the adsorption locator module in Materials Studio were employed. These simulations provided insights into the intermolecular interactions and binding energies between BiOCl_xBr_(1-x) (002) surfaces and RhB or CIP molecules on the kaolinite (001) surface. The formation of BiOCl_xBr_(1-x)@Kaol(002)/RhB and BiOCl_xBr_(1-x)@Kaol(002)/CIP structures was confirmed through these computational studies. The combined experimental and theoretical results highlight the potential of BiOCl_xBr_(1-x)@Kaol nanocomposites as highly efficient, stable, and reusable photocatalysts suitable for large-scale environmental applications in water purification.