Solvothermal Synthesis of Crystalline Phase and Shape Controlled Sn4+-Doped TiO2 Nanocrystals: Effects of Reaction Solvent

The Sn4+-doped TiO2 nanocrystals with controlled crystalline phase and morphology had been successfully prepared through easily adjusting the solvent system from the peroxo-metal-complex precursor by solvothermal method. The Sn4+-doped TiO2 nanocrystals were characterized by XRD, Raman, TEM, HRTEM, XPS, ICP-AES, BET, and UV-vis. The experimental results indicated that the Sn4+-doped TiO2 nanocrystals prepared in the pure water or predominant water system trend to form rodlike rutile, whereas the cubic-shaped anatase Sn4+-doped TiO2 nanocrystals can be obtained in the alcohol system. The growth mechanism and microstructure evolution of the Sn4+-doped TiO2 nanocrystals prepared in the different solvent systems are discussed. The liquid-phase photocatalytic degradation of phenol was used as a model reaction to test the photocatalytic activity of the synthesized materials. It was found that sample Sn4+-doped TiO2 prepared in 1-butanol showed the maximum photoactivity, which attributed to higher band gap, optimal crystalline phase and surface state modifications.