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8561471 
Journal Article 
Photocatalytic degradation of aqueous diclofenac by ZnIn2S4 under visible light 
Feng, Q; Bo, L; Gao, B; Liu, J; Tan, N; Meng, H; He, K 
2017 
Huanjing Gongcheng Xuebao / Chinese Journal of Environmental Engineering
ISSN: 1673-9108 
Science Press 
11 
2 
739-747 
Chinese 
The visible-light-responsive catalyst ZnIn2S4 was prepared by the hydrothermal method and applied to degrade trace levels of the aqueous pharmaceutical compound diclofenac (DCF) under visible-light irradiation. The photocatalytic efficacy and degradation pathway of DCF were investigated. The catalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), and nitrogen adsorption. The trapping of hydroxyl radicals was also determined in this study. The findings indicated that ZnIn2S4 catalyst has a specific surface area of 91.3 m2·g-1 and shows excellent photocatalytic performance under visible light irradiation. DCF removal reached 98% under conditions of 100 μg·L-1 initial concentration, 10 mg·L-1 dosage of ZnIn2S4, and 5 h of reaction time. In comparison, 91% of the DCF was removed after 5 h reaction under light irradiation without the catalyst. Both the photodegradation and photocatalytic degradation of DCF were fit well by a pseudo-first-order kinetic model, and the photocatalytic degradation rate was 1.5 times greater than the photodegradation rate. The photodegradation of DCF mainly occurred via photocyclization, and 2-(8-chloro-9H-carbazol-1-yl) acetic acid was the main intermediate product. More active intermediate products were produced by the oxidation of hydroxyl radicals during the photocatalysis, and main degradation products included 1-chloro-8-methyl-9H-carbazole and 2, 6-dichloro-N-o-tolylbenzenamine. © 2017, Science Press. All right reserved. 
Degradation mechanism; Diclofenac; Photocatalysis; Photodegradation; Visible light; ZnIn2S4