微波助离子液体中Nd掺杂纳米TiO2催化剂的制备及其微波强化光催化活性

Microwave Assisted Preparation of Nd-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Nd掺杂纳米TiO2光催化剂TiO2-Nd。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Nd掺杂量对其光催化活性的影响。试验表明，煅烧温度为650℃、煅烧时间为2 h、微波干燥功率为210 W、微波干燥时间为20 min、离子液体加入量为5.6 mL和Nd掺杂量为n(Nd)/n(Ti) = 0.005时，TiO2-Nd的催化活性最高，且在MW、UV和MW/UV三种降解条件下，TiO2-Nd对甲基橙的降解率分别为11.58%，80.67%，86.59%，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Nd掺杂纳米TiO2降解甲基橙的效果。

Abstract: Using Ti(OBu)4 as the precursor, Nd-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℃), using the three conditions of MW, UV, MW/UV respectively, the effects of the calcinations temperature, the calci- nations time, the power of microwave drying, microwave drying time, the amount of ionic liquid and the Nd doping amount on the photo-catalytic activity of TiO2-Nd for degradation of methyl orange were investigated in the combina- tion of catalytic synthesis of microwave ultrasonic instrument. The tests indicated that the catalytic activity of TiO2-Nd reached the highest level under the following conditions: calcination temperature (650℃), calcination time (2 h), mi-crowave drying power (210 W), microwave drying time (20 min), ionic liquid volume (5.6 mL) and Nd doping amount (n(Nd)/n(Ti) = 0.005). The degradation rate of methyl orange under three conditions were 11.58%, 80.67%, 86.59%, and degradation effect of methyl orange under three conditions: MW/UV > UV > MW. The results showed that MW had a very good synergy with UV and microwave had the effect of strengthening TiO2-Nd degradation of methyl orange.