Thermal formation of silicon-doped TiO2 thin films with enhanced visible light photoelectrochemical response

Silicon-doped TiO2 thin films were fabricated by annealing titanium metal sheet embedded in SiO2 powders and characterized by X-ray photoemission spectroscopy and photoelectrochemical measurements. The results showed that the content of silicon in the doped TiO2 thin films was proportional to the annealing time and temperature. Enhanced visible light response, more negative flat band potential and higher carrier density were demonstrated by the electrochemical measurement. The technique proposed in this paper can be also applicable to fabricate other doped TiO2 thin films based on the corresponding oxide bath. A “solid-state oxide bath” approach was developed to fabricate silicon-doped TiO2 thin films by annealing titanium sheet embedded in SiO2 powders and its enhanced visible light photoelectrochemical response was demonstrated. [Display omitted] ► Si-doped TiO2 thin films were successfully fabricated in-situ by a one-step “oxide bath” method. ► The doping content of silicon was proportional to the thermal treatment time and temperature. ► Enhanced visible light response was demonstrated by photoelectrochemical measurement. ► The resulted sample has more negative flat band potential and higher carrier density. ► The method is applicable to the preparation of other doped TiO2 based on the corresponding oxides.