Well-Defined Single and Bundled Rutile Nanorods in Mesoporous Silica for Efficient Hydrogen Evolution Photocatalysis

Rutile nanorods (single nanorods and connected nanorods) with diameter similar to the pore size of the template (cylindrical mesopore of SBA-15 with a pore diameter of 8 nm) are prepared by infiltration of the partially hydrolyzed titanium alkoxide and the subsequent in situ crystallization in the mesopore by reaction with HCl vapor at room temperature. Morphological variation is achieved by varying the loading amount of the titanium dioxide precursor in the mesoporous silica. The crystallization is followed by Raman spectra and X-ray diffraction patterns. The single rutile nanorods with the diameter of 5 nm and the connected rutile nanorods with the diameter of 7 nm are successfully collected by dissolving the silica template (SBA-15) using an aqueous solution of sodium hydroxide. Both supported and isolated rutile nanorods are active for hydrogen evolution from an aqueous methanol solution by ultraviolet (UV) irradiation.