A simple, rapid, one-step approach for preparation of Ag@TiO2 nanospheres with multiple cores as effective catalyst

Abstract

Novel Ag@TiO₂ nanostructures with multiple Ag nanoparticles as cores and a crystalline TiO₂ as the outer shell have been successfully achieved via a facile and one-step solvothermal route. The synthetic approach is simple, rapid, and environmentally friendly, in which no any sacrificial template, toxic reagent or surfactant is emploited. Moreover, the as-prepared Ag@TiO₂ products show an uniform and spherical morphology as well as a large specific surface area (225.9 m² g⁻¹). The time-dependent experiments reveal that the formation of Ag@TiO₂ nanospheres includes a nucleation, aggregation and self-assembly process. Apart form this, the rattle-type Ag@TiO₂ nanoparticles can be also obtained by only tuning the amount of tetrabutyl titanate (TBOT) added in the precursor. When employed as catalyst for reduction of 4-nitrophenol (4-NP), the Ag@TiO₂ nanospheres prepared exhibit a superior catalytic activity and a good cycle stability, benefiting from their unique multiple-cored nanostructure and the effective synergistic effect between Ag nanoparticles and TiO₂ shell. The present method also provides a great possibility for preparation of other metal@TiO₂ nanocomposites and their promising applications in catalysis, electrochemistry, and purification, and so on.