Laser irradiation synthesis and photocatalytic properties of TiO2-SiO2 hybrid thin films

In this study, we introduce a noble method for the fabrication of highly crystalline hybrid TiO2-SiO2 thin films using laser irradiation under ambient conditions. Upon light absorption at the interface between TiO2 sol-gel film and Si wafer during the laser irradiation process, the TiO2 gel film coated on the Si wafer is transformed into anatase TiO2 film, and the surface of underlying Si wafer is oxidized to a 20.63 mu m thick SiO2 film composed of nano-spheres with average diameter of 24.12 nm. The photocatalytic characteristics of the TiO2-SiO2 hybrid film on methylene blue and its discriminated morphologies are compared with those of a TiO2 film fabricated by conventional thermal annealing. The TiO2-SiO2 hybrid film shows enhanced super-hydrophilicity and superior photocatalytic characteristics, while thermally annealed 0.16 mu m thick TiO2 films exhibit hydrophobic and low photocatalytic properties. The laser assisting process is promising for the fabrication of highly crystalline TiO2-SiO2 hybrid film with super-hydrophilic and photocatalytic characteristics.