SiO2@TiO2 Core Shell Nanoparticles Deposited on 2D-Layered ZnIn2S4 to Form a Ternary Heterostructure for Simultaneous Photocatalytic Hydrogen Production and Organic Pollutant Degradation

It is challenging to design and prepare difunctional photocatalysts for simultaneous photocatalytic wastewater purification and hydrogen (H-2) energy production. In this study, a novel ternary heterostructure pholocatalyst, ZnIn2S4SiO2@TiO2 (ZIS@SIO2@TiO2) was successfully prepared by simple sol-gel and solvothermal methods. The SiO2 nanospheres were used as a support to prevent the aggregation of TiO2 nanoparticles efficiently. The SiO2@TiO2 nanoparticles were uniformly inserted into the 2D-layered flowerlike ZnIn2S4 to form a ternary heterostructure that can efficiently improve the separation and transportation of photoinduced electron-hole pairs. As expected, the 150%-ZIS@SiO2@TiO2 nanocomposite exhibited an excellent rate of H-2 production under simulated sunlight (618.3 mu mol g(-1) h(-1)) which was 229 and 3.3 times higher than the binary SiO2@TiO2 nanoparticles and pure ZnIn2S4. Furthermore, the degradation efficiency of methylene blue reached 99.7% during the H-2 production process. These findings provided possibilities to couple energy conversion with environmental restoration.