离子液体-水的混和溶剂中，纳米TiO2的制备与表征

以钛酸正丁酯为前驱物，采用溶胶-凝胶低温水热方法，以离子液体(1-乙基-3-甲基咪唑醋酸盐)和水为混合溶剂，制备了锐钛矿相的纳米二氧化钛。产物经XRD，TEM，N₂吸附-脱附等表征，结果表明与纯水相比，混和溶剂中制备的二氧化钛具有较高的纯度，结晶度和热稳定性，且缩短反应时间到24 h，所得颗粒尺寸10 nm与在纯水中反应48 h所得颗粒尺寸7 nm相当，说明离子液体的存在可促进锐钛矿相二氧化钛的结晶和生长。另外，该产物表面积可达238 m²·g^-1。本文还进一步研究了该产物对甲基橙水溶液的光降解作用，结果表明，用此方法制备的TiO₂对甲基橙降解作用优于商业P25二氧化钛。

Synthesis and Characterization of Titania Powders from Mixture of Ionic Liquid-Water

Titania was prepared in the mixture solvent of ionic liquid (1-ethyl-3-methyl-imidazole acetate EmIm⁺AcO^-]) and water by sol-gel low temperature hydro-thermal treatment of tetrabutyl titanate. The sample was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform-IR spectroscopy and nitrogen adsorption-desorption isotherms. The results show that the anatase titania, with an average grain size of 10 nm and specific surface area of 238 m²·g^-1, is better in purity, crystallinity and thermal stability compared with that prepared in pure water. Moreover, the reaction time in mixture solvent is reduced to half of that in pure water for about the same crystalline size. The photocatalytic activity of the samples was evaluated by photocatalytic decolorization of methyl orange in water. The results also indicate that the titania prepared in this work displays a better activity than the commercial degussa P25.