Self-assembly of Ag-TiO2 nanoparticles: Synthesis, characterization and catalytic application

The formation of Ag clusters on titanium oxide (TiO₂) nanoparticles was achieved by selfassembly process and calcination. The obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet visible spectroscopy (UV-Vis), and conventional techniques (XRD, TEM and UV-Vis) were used to identify Ag particles on the TiO₂ surfaces. The results show that Ag-TiO₂ particles can be applied to improve catalytic activity of the epoxidation of styrene oxides. Styrene oxide is the main product of catalytic reaction with H₂O₂ as the oxidant by using Ag-TiO₂ nanoparticles as catalysts. High catalytic activitity of styrene oxide can be obtainable at 80 °C. The reaction temperature, reaction time, the molar ratio of H₂O₂/styrene and solvent affect greatly the catalytic epoxidation of styrene.