ZnIn2S4@ZrDP composite: its preparation and high catalytic activity in photodegradation reactions

Abstract

In this study, a zirconium phosphonate, ZrDP, with a rigid multi-nitrogen heterocycle and hierarchical pores in its framework was used to construct a ZnIn₂S₄@ZrDP composite by in situ surface loading of ZnIn₂S₄. The multi-nitrogen heterocycle in the carrier promoted light absorption and facilitated energy transfer to ZnIn₂S₄, thereby accelerating the separation of photogenerated electron–hole pairs in the semiconductor. ZnIn₂S₄ was uniformly dispersed on the surface of ZrDP, which increased the negative charge density of the composite, enhanced its adsorption capacity toward cationic species and promoted light absorption. Compared with ZnIn₂S₄, ZnIn₂S₄@ZrDP exhibited higher catalytic activity and good recyclability in the photodegradation reactions of some cationic dyes, such as methylene blue, rhodamine B, methyl orange and malachite green, and rhodamine B could be completely degraded under mild conditions. ˙O₂⁻ and h⁺ produced in the reaction were identified as the main reactive species responsible for the oxidation process.