Synergistic photocatalytic degradation of amoxicillin by precious metal supported TiO₂ with KBrO₃

To improve the photocatalytic efficiency of TiO₂ for amoxicillin removal, a series of precious metals catalysts (M/TiO₂, M=Ru, Rh, Pd, Ag, Ir, Pt or Au) were prepared by light deposition method. The synergistic photocatalytic activity of M/TiO₂ with KBrO₃ for degradation of amoxicillin (20 mg/L) in aqueous solution was researched under UV light (365 nm). The effects of metal loading, catalyst concentration, KBrO₃ concentration and pH on the photocatalytic activity of Rh/TiO₂ with KBrO₃ were explored. The results show that the photocatalytic activity of M/TiO₂ is closely related to its work function and KBrO₃has a greatly synergistic role on M/TiO₂. Under the conditions of 0.1% Rh loading, Rh/TiO₂ concentration of 0.15 g/L, KBrO₃ concentration of 0.5 mmol/L and reaction liquid pH value at 5, the amoxicillin can be degradated completely within 90 min. Furthermore, the results of kinetic study show that the degradation reaction can be expressed by the first-order reaction kinetic model.