微波助离子液体中S掺杂TiO₂催化剂的制备及其微波强化光催化活性

Microwave Assisted Preparation of S-Doped Nano-TiO₂ Photo-Catalysts in Ionic Liquids and Its Microwave Enhanced Photo-Catalytic Activity

摘要: 在离子液体介质中，采用溶胶–凝胶法，以钛酸正丁酯为前驱物，合成S掺杂纳米TiO₂光催化剂TiO₂-S。采用IR、XRD对催化剂的结构进行了表征，以甲基橙为模拟污染物，在微波超声波组合催化合成仪中，在恒温(25℃)下，分别利用微波辐射(MW)、紫外光照(UV)及微波辐射 + 紫外光照(MW/UV)三种降解条件，考察了煅烧温度、煅烧时间、微波干燥功率、微波干燥时间、离子液体用量和S掺杂量对其光催化活性的影响。试验表明，煅烧温度为600℃、煅烧时间为2 h、微波干燥功率为210 W、微波干燥时间为25 min、离子液体加入量为5.6 mL和S掺杂量为n(S)/n(Ti) = 2时，TiO₂-S的催化活性最高，且在MW、UV和MW/UV三种降解条件下，TiO₂-S对甲基橙的降解率分别为7.26%，75.49%，82.12%，这表明微波与紫外光照有很好的协同作用，微波–紫外光照具有强化S掺杂纳米TiO₂降解甲基橙的效果。

Abstract: Using Ti(OBu)4 as the precusor S-doped nano-TiO₂ photo-catalysts were prepared by the sol-gel method in ionic liquids. The IR and XRD were used to characterize the structure of the catalysts. At a constant temperature (25°C), using respectively the three degradation conditions of MW, UV and MW/UV, the effects of the calcinations temperature, the calcinations time, the power of microwave drying, microwave drying time, the amount of ionic liquid and the S doping amount on the photocatalytic activity of nanoparticle TiO₂ for degradation of methyl orange were investigated in the combination of catalytic synthesis of microwave ultrasonic instrument. The tests indicated that the highest catalytic activity of nanoparticle TiO₂ under the following condition: calcination temperature of 600°C, calcination time of 2 h, microwave drying power of 210 W, microwave drying time of 25 min, ionic liquid added in an amount of 5.6 mL and S doped amount of n(S)/n(Ti) = 2. The degradation rate of methyl orange under three conditions of MW, UV and MW/UV were 7.26%, 75.49% and 82.12% respectively. This reveals that MW has a very good synergy with UV, and microwave has the effect of strengthening S-doped nano-TiO₂ degradation of methyl orange.