Engineering surface oxygen vacancies to steer electron flow for perfluorooctane sulfonate mineralization by visible...

The extreme persistence of perfluorooctane sulfonate (PFOS) in water resources challenges conventional treatment methods and poses significant environmental health risks. Here, we demonstrate that engineering surface oxygen vacancies in calcium titanate (CaTiO₃) perovskite creates an efficient visible-light-driven photocatalyst for PFOS mineralization. The sol-gel-synthesized CaTiO₃ nanospheres possess abundant surface oxygen vacancies that enhance visible-light absorption and, more importantly, direct photogenerated electrons to adsorbed PFOS molecules. This electron transfer mechanism achieves 97.8% PFOS degradation under visible light and a remarkable 66.5% defluorination ratio, significantly outperforming the conventional hydrothermal catalyst. Furthermore, the catalyst immobilizes released fluoride ions as CaF₂ on its surface, preventing secondary pollution. Our work provides a sustainable and zero‑carbon strategy for destroying persistent pollutants by precisely controlling electron pathways through defect engineering.