Fabrication of wool ball-like F-doped BiOCl0.4Br0.3I0.3 composite for effective sulfamethazine photocatalytic degradation

Novel material wool ball-like F-doped BiOCl 0.4 Br 0.3 I 0.3 has been successfully fabricated via a facile solvothermal method. In this work, the as-synthesized catalyst was characterized to examine the structure, morphology, optical and electrochemical properties. The catalyst was used in sulfamethazine degradation under visible-light irradiation. The optimized photocatalyst F-BiOCl 0.4 Br 0.3 I 0.3 (Bi:F = 3:2) exhibits superior activity and the degradation efficiency can reach 99.6 % in pH 6 within 60 min. There are two reasons to explain it: (i) The F-BiOCl 0.4 Br 0.3 I 0.3 has narrow band gap; (ii) Wool ball-like morphology can cause multiple reflections of the irradiated light, and availably prolong the action time. The primary oxidative species are holes and superoxide radicals. The possible degradation mechanism was discussed based on the experimental results.