Synthesis, characterization, and photocatalytic properties of Ag modified hollow SiO2/TiO2 hybrid microspheres

Well-defined Ag modified hollow SiO2/TiO2 hybrid spheres were successfully prepared through a two-step hydrothermal synthesis based on polystyrene templates followed by calcination. The employed protocol involves successive coating of the functionalized polystyrene (PS) template with SiO2 and TiO2 layers, followed by Ag doping using AgNO3 as the Ag source. Finally, a calcination process is carried out for the elimination of the PS core, thermal decomposition of AgNO3 to yield Ag nanoparticles and crystallization of the amorphous TiO2 layer simultaneously to acquire the final products. With this method, a complete, homogeneous and smooth hollow SiO2/TiO2 hybrid structure with uniformly dispersed Ag nanoparticles was formed. Photocatalytic properties of the fabricated Ag modified hollow SiO2/TiO2 hybrid spheres has been investigated for the degradation of rhodamine B (RhB). Ag deposition significantly enhanced the RhB photodegradation under visible light irradiation due of the Schottky barrier formed at the Ag–TiO2 interface, which serve as the electron trap, facilitating the separation of electrons and holes.

Figure optionsDownload as PowerPoint slideResearch highlights▶ Ag modified hollow SiO2/TiO2 hybrid spheres. ▶ High surface area and small particle size of the photocatalyst. ▶ Dye sensitization. ▶ Effective degradation of RhB under visible light irradiation.