Fabrication of Shape-Controlled Au Nanoparticles in a TiO2-Containing Mesoporous Template Using UV Irradiation and Their Shape-Dependent Photocatalysis

A SiO2–TiO2 template with ordered tubular mesochannels has been prepared by the sol–gel method. Au nanorods are deposited in the tubular mesochannels of the SiO2–TiO2 template, and the shape of Au is changed from nanorods to nanospheres by ultraviolet irradiation during thermal deposition. The photocatalytic activity of mesoporous SiO2–TiO2 with/without Au nanorods/nanospheres is evaluated. Deposition of Au in the mesoporous SiO2–TiO2 template enhances the photocatalysis of TiO2. Interestingly, the sample containing Au nanorods exhibits higher photocatalytic activity than that with Au nanospheres. Photocatalysis by exciting surface plasmon resonance is not detected in the composite samples regardless of the shape of the deposited Au nanoparticles.