Facile in-situ Solvothermal Method to synthesize double shell ZnIn2S4 nanosheets/TiO2 hollow nanosphere with enhanced photocatalytic activities

The design and construction of efficient visible light responsive composite photocatalysts with intimate interfacial contacts in photocatalytic field have attracted huge interest. Herein, a double-shelled ZnIn2S4 nanosheets/TiO2 hollow composite single nanosphere (ZIS/TiO2) was first fabricated by a facile hydrothermal process, where 2D ZnIn2S4 nanosheets self-assembled on the external surface of TiO2 hollow nanosphere to form the double-shelled hollow single sphere. The morphologies, structures, optical properties of as-prepared double-shelled ZIS/TiO2 hollow nanospheres were characterized in detail. The photocatalytic activities of double-shelled ZIS/TiO2 nanospheres for the photodegradations of Tetracycline hydrochloride, Levofloxacin and Rhodamine B under visible light irradiation have been investigated. Compared to pure TiO2 and ZnIn2S4, the obtained ZIS/TiO2 samples have significantly improved photocatalytic performances. The most optimal photocatalytic activity of ZIS/TiO2-2 nanocomposite with 64 wt% ZnIn2S4 nanosheets coated is observed, and its degradation rate constant is 2.32 and 2.14 times as high as those of pure TiO2 and ZnIn2S4. The superior photocatalytic performance of ZIS/TiO2 nanocomposite can be ascribed to its unique double shell hollow structure and the synergistic effect between ZnIn2S4 and TiO2. Our result provides some guidance for designing novel morphologies of composite photocatalyst with good photocatalytic performance.