微波助离子液体中锌掺杂纳米TiO_2的制备及微波强化光催化氧化活性

Preparation of Zn-doped nano-TiO_2 photocatalyst under microwave irradiation in ionic liquid and its microwave strengthen photocatalytic oxidation activity

在1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)离子液体介质中,采用溶胶-凝胶法和微波干燥法制备Zn掺杂的纳米TiO2光催化剂TiO2-Zn。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)和微波辐射联合紫外光照(MW-UV)降解方式,考察离子液体用量、Zn掺杂量、微波干燥功率、微波干燥时间、焙烧温度和焙烧时间等因素对TiO2-Zn光催化活性的影响。结果表明,在离子液体用量为5.6 mL、n(Zn)∶n(Ti)=0.012 5∶1、微波干燥功率210 W、微波干燥时间17.5 min、焙烧温度600℃和焙烧时间2 h条件下,制得的TiO2-Zn光催化剂具有较高的光催化活性。TiO2-Zn光催化剂在3种降解方式中对甲基橙的降解效果为:MW-UV>UV>MW,表明微波辐射-紫外光照具有较好的协同作用效果。

Zn-doped nano-TiO2 photocatalysts were prepared in ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate （ [ Bmim ] PF6 ） by sol-gel and microwave drying method. The influence of ionic liquid dosage, Zn/Ti molar ratio, microwave drying power and drying time, calcination temperature and calcination time on the photocatalytic activities of TiO2-Zn catalysts was investigated orange as simulated pollutant and ultraviolet lamp as the light source. The results sho by using methyl wed that TiO2-Zn catalyst exhibited higher photocatalytic activity under the optimal condition as follows：ionic liquid dosage 5.6 mL, n （Zn） ： n （ Ti ） = 0.012 5： 1, microwave power 210 W, microwave drying time 17.5 min, calcination temperature 600 ℃ and calcination time 2 h. The sequence of degradation effect for methyl orange over TiO2-Zn catalyst under three irradiation conditions was ： MW-UV 〉 UV 〉 MW, which indicated that MW-UV irradiation possessed good synergistic effect.