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以四氯化钛为钛源,离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)/水为混合溶剂,采用液相水解-沉淀法合成纳米TiO2光催化剂。以苯酚为模型物,考察了TiO2紫外下催化活性。采用XRD、TG/DSC、TEM、FTIR、DRS、低温N2物理吸附-脱附等技术对催化剂的结构进行表征。结果表明,在离子液体/水混合溶剂中合成TiO2的光催化活性较纯水溶剂中合成TiO2的光催化活性高,且在较宽的活化温度范围内(500~700℃)都表现出较高的光催化活性。这一结果可归因于在离子液体/水混合介质中合成的TiO2颗粒小、分散性好、比表面积大(138 m2/g)、吸附性能强。另外,离子液体的存在一定程度上降低了TiO2粒子表面羟基数量及表面酸度,提高了锐钛矿相TiO2向金红石相转变的温度。
Titanium tetrachloride as titanium source and ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim] PF6) / water as mixed solvent were synthesized by liquid-phase hydrolysis-precipitation method. With phenol as a model, the catalytic activity of TiO2 under UV was investigated. The structure of the catalyst was characterized by XRD, TG / DSC, TEM, FTIR, DRS and N2 adsorption-desorption. The results showed that the photocatalytic activity of TiO2 synthesized in the ionic liquid / water mixed solvent was higher than that of TiO2 synthesized in pure water solvent, and higher in the range of activation temperature (500 ~ 700 ℃) Photocatalytic activity. This result can be attributed to the small particle size, good dispersion and high specific surface area (138 m2 / g) of TiO2 particles synthesized in the ionic liquid / water mixed media with strong adsorptivity. In addition, the presence of ionic liquid reduced the number of hydroxyl groups and surface acidity of TiO2 particles to a certain extent, and increased the temperature of anatase phase TiO2 to rutile phase.