The one-step synthesis of multiphase SnS2 modified by NH2-MIL-125(Ti) with effective photocatalytic performance for Rhodamine B under visible light

The emission of organic dye wastewater poses a great threat to the ecological environment. Therefore, it is necessary to prepare environment-friendly photocatalytic materials with high photocatalytic performance to degrade organic dyes. In this work, a new composite photocatalyst SnS2/NH2-MIL-125 (Ti) was formed by loading the multiphase SnS2 of quantum dots (QDs) and hexagonal nanodiscs (NDs) on the NH2-MIL-125 (Ti) through one-step hydrothermal method, then used it to remove 40 mg/L Rhodamine B (RhB) under visible light. Compared with SnS2 and NH2-MIL-125 (Ti), the photocatalytic degradation activity of the 12 wt% SnS2/NH2-MIL-125 (Ti) was enhanced by 2.4 and 2.1 times respectively, reaching 90.5%, after 80 min of visible light irradiation. The four times recycling test shows that this photocatalyst has outstanding stability and durability. Through analysis, NH2-MIL-125 (Ti) modified SnS2 can improve visible light absorption, provide more active sites and inhibit photoelectron-hole recombination, thus enhancing photocatalytic activity. Superoxide radical (•O2−) and hole (h+) were determined to be the key active substances in the process by the reaction substance capture experiment. The photodegradation mechanism of RhB is also investigated and studied in detail. This novel multiphase SnS2/NH2-MIL-125 (Ti) material provides a new perspective for the design of organic-inorganic composite photocatalysts with excellent performance and improved stability, and has potential application in environmental purification.