Effect of alcohol solvents on TiO2 films prepared by sol-gel method

The TiO2 (anatase) films were prepared by sol-gel method using titanium (IV) isopropoxide (TTIP) as a precursor and polyvinylpyrrolidone (PVP) as a polymeric precursor dissolved in different alcohol solvents (methanol, ethanol, isopropanol and 1-butanol) and were heated treatment at 450 °C for 1 h. In this research, the alcohol solvents have significant influence on the morphology, crystalline degree and energy band gap of TiO2. The number of carbon, boiling point, dielectric constant and viscosity of alcohol solvents were the main factor influencing the size of TiO2 nanoparticles. The alcohol solvent with higher boiling point and viscosity, and long length of carbon chain can lead to the smaller crystallite size. The number of carbon and viscosity of solvent and crystallite size can play the important role in the agglomeration of particles. The energy band gaps of the films determined by UV-visible spectroscopy were in the 3.00-3.30 eV range.