Synthesis and characterization of TiO2 photocatalytic thin films prepared from refluxed PTA sols

The peroxo titanic series refluxed sols (RS) were synthesized using titanyl sulfate (TiOSO4), ammonia as raw materials and peroxide (H2O2) as chelating agent by refluxing method from peroxo titanic acid sol. The transparent nano anatase TiO2 thin films fixed on glass slide substrates were prepared from the RS precursors by dip-coating, then dried under infrared light and calcined at 500 °C for 30 min. Several characterization techniques, such as FT-IR, XRD, TEM, TG-DTA, SEM, were applied to characterize the RS sol and TiO2 thin films. The results indicated that the RS sols were flavescent, semitransparent and alkalescent, the RS sols kept stable at room temperature, and contained needle-like TiO2 anatase crystals which were 30∼80 nm in length, 15–20 nm in diameter and well distributed in the sols. The TiO2 films were uniform, compact and transparent. The degradation of 10 mg/L methyl orange results illustrated that the RS-6 TiO2 thin films showed the best photocatalytic activities, the decoloration rate of the methyl orange solution with RS-6 TiO2 thin films reached 99% after irradiated 160 min under UV light, which proved TiO2 films prepared from RS sol showed high photocatalytic activities.