Synthesis, characterization and photocatalytic activity of Au/SiO2@TiO2 core-shell microspheres

Abstract

By using HAuCl4 as the gold precursor, spherical Au@SiO2/TiO2 core-shell nanostructures were prepared with the sol-gel method and ethanol reflux. The preparation process was convenient and fast. The obtained samples were characterized by UV-Vis, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The results suggested that these spherical particles were in uniform distribution of particle size and with excellent monodispersity. Gold nanoparticles were successfully loaded on the core-shell structure, and TiO2 nanoparticles were functionalized. With the functionalization of gold nanoparticles, Au@SiO2/TiO2 nanoparticles showed excellent photocatalysis activity for the degradation of methyl orange. The possible mechanism of catalytic degradation was discussed in the paper.