Facile synthesis of oxygen vacancy-rich BiMnx composites for enhancing antibiotic removal driven by LED visible light

NaBiO 3 is a low-cost photocatalyst with good performance for organic removal. Oxygen vacancies (OVs) play crucial roles in mediating oxygen activation and electron-hole separation during visible light-driven photocatalysis. In this study, Mn ions were doped into the commercial NaBiO 3 by a facile in-situ technique to construct OVs for enhancing sulfamethazine (SMT) removal. By doping 0.001–0.01 mmol of Mn 2 + ions, abundant OVs were formed on the initial NaBiO 3 surface, endowing the as-prepared BiMn x composites (e.g. BiMn 0.001 ) with a fast kinetic (first-order rate constant k 0.68 h −1 ) and a high efficiency (>99 % within 6 h) for SMT degradation. Excellent removal of SMT could be attained across a broad pH range (i.e. pH 0 5–9) using BiMn 0.001 as the photocatalyst, which could harvest full-spectrum LED white light and showed anti-interference to common water co-existent constituents. Increasing solution temperature was also beneficial for SMT removal. Reactive species including 1 O 2 , holes and electrons played dominant roles for SMT removal. Based on HPLC-MS, the degradation intermediates were identified, and a degradation pathway for SMT was formulated in the BiMn x /LED system. The results may shed some light for constructing OVs on catalyst surfaces and preparing LED visible light-responsive photocatalysts for antibiotic removal.