Fabrication of hydroxyl group modified monodispersed hybrid silica particles and the h-SiO2/TiO2 core/shell microspheres as high performance photocatalyst for dye degradation

The monodisperse hybrid silica particles (h-SiO2) were firstly prepared by a modified sol–gel process and the surface was modified in situ with double bonds, then abundant carboxyl moieties were introduced onto the surface of the silica core via thiol–ene click reaction. Afterward, the h-SiO2/TiO2 core/shell microspheres were prepared by hydrolysis of titanium tetrabutoxide (TBOT) via sol–gel process in mixed ethanol/acetonitrile solvent, in which the activity of TBOT could be easily controlled. The carboxyl groups on the surface of silica particles promote the formation of a dense and smooth titania layer under well control, and the layer thickness of titania could be tuned from 12 to 100 nm. The well-defined h-SiO2/TiO2 core/shell structures have been confirmed by electron microscopy and X-ray photoelectron spectroscopy studies. After calcination at 500 °C for 2 h, the amorphous TiO2 layer turned into anatase titania. These anatase titania-coated silica particles showed good photocatalytic performance in degradation of methyl orange aqueous solution under UV light.

A new type of h-SiO2/TiO2 core/shell microspheres exhibited excellent photocatalytic activity was prepared using carboxyl group modified silica particle as core and anatase titania as shell.Figure optionsDownload high-quality image (129 K)Download as PowerPoint slideResearch highlights
► Surface of h-SiO2 was modified by carboxyl moieties via thiol-ene click reaction.
► The carboxyl groups promoted the formation of a dense and smooth titania layer under well control.
► Anatase titania shell showed good photocatalytic performance in degradation of methyl orange.