微波法离子液体介质中纳米TiO2光催化剂制备及催化活性

以钛酸丁酯为前驱物，在离子液体1-丁基-3-甲基咪唑六氟磷酸盐、水和无水乙醇组成的混合溶剂中，采用溶胶-凝胶法和微波干燥，制备了纳米TiO₂光催化剂，并用XRD、TG和IR对催化剂结构进行了表征。以甲基橙为模拟污染物，高压汞灯为光源，考察了离子液体用量、焙烧温度、微波功率和微波干燥时间等对TiO2光催化剂活性的影响。结果表明，在n（［Bmim］PF₆）∶钛酸丁酯）=3.0、焙烧温度550 ℃、微波干燥功率210 W和微波干燥时间20 min条件下，离子液体介质中用微波干燥所得的纳米TiO₂催化剂具有较高的光催化活性，90 min使甲基橙降解率达97.8%，表明离子液体的存在抑制了TiO₂由锐钛矿相向金红石相的转变，并起增大TiO₂比表面积及表面羟基含量的作用

Microwave-assisted preparation of nanoparticle TiO2 photocatalyst in ionic liquids and its activity

Using Ti(OBu)₄ as the precursor, nanoparticle TiO₂ photocatalysts were prepared in ionic liquids under microwave irradiation and characterized by XRD，TG and IR. Effects of ionic liquid quantity，calcination temperature，microwave power and microwave drying time on photocatalytic activity of the nanoparticle TiO₂ for degradation of methyl orange were investigated, using ultraviolet lamp as the irradiation source. The results indicated that the nanoparticle TiO₂ obtained in ionic liquid by microwave drying exhibited higher photocatalytic activity, with methyl orange degradation rate of 97.8% in 90 min; ionic liquid inhibited the crystal transfer of TiO₂ from rutile to anatase phase and enhanced surface areas and the concentration of hydroxyl on surface of the photocatalysts.