Enhanced photocatalytic degradation of bisphenol A by magnetically separable bismuth oxyiodide magnetite nanocomposites under solar light irradiation

Bismuth oxyiodide/magnetite (BiOI/Fe₃O₄) nanocomposites were synthesized by a hydrothermal reaction. The synthesized BiOI/Fe₃O₄ was used to remove bisphenol A (BPA) from an aqueous solution under simulated solar light. The molar ratio of Bi to Fe in BiOI/Fe₃O₄ significantly affected BPA degradation, with the optimal BiOI/Fe₃O₄ (2:1) ratio in the composites. Optimum operating conditions such as a catalyst dosage of 1.0 g/L, an initial BPA concentration of 10 mg/L, and pH 7 gave a complete degradation of completely removed BPA within 30 min. The primary reactive oxygen species were verified as superoxide radicals and holes in oxidative species experiments. The magnetic BiOI/Fe₃O₄ could be easily collected from an aqueous solution by an external magnet, and its reusability was successfully demonstrated through recycling experiments. Furthermore, the derivatives in BiOI/Fe₃O₄ photocatalytic reactions were investigated, and a possible BPA degradation pathway was proposed. These results show that BiOI/Fe₃O₄ nanocomposites have great potential for BPA removal from water and wastewater treatment systems.