微波助离子液体中氮掺杂TiO2催化剂的制备及其微波强化光催化活性

Preparation of N-doped TiO2photo-catalyst under microwave irradiation in ionic liquid and microwave strengthen photo-catalytic oxidation activity

在室温离子液体介质中，采用溶胶-凝胶法以及微波干燥的方法制备了氯掺杂的光催化剂TiO2-N。在室温条件下，以甲基橙为模拟污染物，在微波超声波组合催化合成仪中，分别利用微波辐射（MW）、紫外光照（UV）和微波辐射一紫外光照（MW—UV）三种降解方式，主要考察了N掺杂量、微波干燥功率、微波干燥时间、煅烧温度和煅烧时间等因素对TiO2-N光催化活性的影响。结果表明，在离子液体用量为5．6mL、N掺杂量n（N）／n（Ti）=3：1、微波干燥功率210W、微波干燥时间20min、煅烧温度600℃、煅烧时间2h的条件下所制得的TiO2-N光催化剂具有较高的光催化活性；TiO2-N光催化剂在三种降解方式下对甲基橙的降解效果为：MW—UV〉UV〉MW，这表明微波与紫外光照有较好的协同作用，即微波一紫外光照具有强化TiO2-N催化剂降解甲基橙的效果。

N-doped nano-TiO2 photo-catalysts were prepared by microwave drying method in ionic liquid 1-butyl-3 methylimidazolium hexafluorophosphate. At a constant temperature （25 ℃）, using respectively the three conditions of MW, UV, MW-UV the effects of the study fo- cused on the influences of N/Ti mole ratio, microwave drying power and drying time, calcination temperature and calcination time for degradation of methyl orange were investigated in the combination of catalytic synthesis of microwave ultrasonic instrument. The results indicated that the best preparing condition of TiOz-N catalyst was as follows： ionic liquid dosage 5,6 mL, n（N）/n（Ti）=3： 1, microwave power 210 W, microwave drying time 20 rain, calcination temperature 600 ℃ and calcination time 2 h. And more the TiO2-N catalyst with the best preparing condition exhibited higher photo-catalytic activity. The degradation rate of methyl orange under three conditions were 21.2%, 95.2%, 98.7%, and degradation effect of methyl orange under three conditions： MW-UV〉UV〉MW. Description MW had a very good synergy with UV, microwave had the effect of strengthening N-doped nano-TiO2 degradation of methyl orange.