Flower-like ZnIn2S4 microspheres with highly efficient catalytic activity for visible-light-driven sulfamethoxazole photodegradation.

Photocatalysis using ZnIn 2 S 4 (ZIS) is demonstrated as a highly efficient zero carbon emission technology using solar energy as the only energy input. In this study, flower-like ZIS microspheres in perfect shape has been successfully prepared by a facile hydrothermal route for the effective degradation of sulfamethoxazole (SMX) in the visible light irradiation. The microsphere exhibits a better spherical shape with uniform particle size of 4–5 µm and large petals of ~10 nm thickness. The initial effect of ZIS nanostructure adjustment is by changing the pH value in the hydrothermal process. The experimental results showed that the flower-like ZIS microspheres synthesised via hydrothermal treatment at pH 1.0 over 16 h at 160 °C have a degradation efficiency of over 90% SMX. The reason is ascribed to more efficient charge separation replying on the specific nanostructure with a large interface contact area of ZIS. In addition, the optimally initial pH in sulfamethoxazole (SMX) degradation system at the highest photocatalytic efficiency is 5.0 approximately. The dominant radical species, namely O 2 •−, is demonstrated by using electron paramagnetic resonance technology. This study provides a facile synthesis method for the preparation of highly efficient visible light photocatalysts. [Display omitted] • A facile hydrothermal method can obtain flower-like ZnIn 2 S 4 with large 'petals'. • ZnIn 2 S 4 with high activity is due to efficient charge separation and transfer. • Photogenerated electrons were successfully transformed to reactive oxygen species. • Optimized ZnIn 2 S 4 possesses remarking reusability towards SMX photodegradation. [ABSTRACT FROM AUTHOR]