Photocatalytic Activities of TiO2 Nanopowders by Hydrothermal Synthesis in Different Solution Medium
不同介质中水热合成纳米TiO2粉体及其光催化性能研究

TiO2 nanopowders were prepared by hydrothermal synthesis in distilled water, three small organic compounds (n-butyl alcohol, propane diacid and ethylenediamine) and three inorganic acids (HNO3, H2SO4 and HCl) using the titanium n-buoxide as raw material. The product was characterized by powder X-ray diffraction (XRD) and transmission electron microscope (TEM). The effect of different solvent medium on the crystal phase composition, particles size and morphology of the product was investigated. The result shows that anatase TiO2 with non-uniform grain size is obtained in distilled water. The ability to retard the anisotropic growth of anatase is as follows: n-butyl alcohol>propane diacid>ethylenediamine. Under the same experiment condition, rutile, anatase and mixed crystallite of anatase and rutile TiO2 powders are obtained in HCl, H2SO4 and HNO3 medium, respectively. The result of photocatalytic degradation methyl orange shows that the photocatalytic activity of mixed crystallite of anatase and rutile TiO2 powders is higher than that of the pure anatase TiO2 powders. The photocatalytic activity of pure rutile TiO2 powders is worst.