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采用溴化1-丁基-3-甲基咪唑([Bmim]Br)离子液体辅助水热合成法制备了光催化剂Bi VO4。以高压氙灯作为可见光源,亚甲基蓝为目标污染物,考察反应温度、p H、反应时间和离子用量等制备条件对Bi VO4的可见光催化活性的影响,确定了最佳制备条件。并采用XRD、SEM和UV-Vis漫反射等分析手段对催化剂的晶相、形貌和光学特性进行了表征。结果表明,在离子液体加入量为2 m L、p H=4、反应温度为180℃、反应时间为4 h的条件下,制得的Bi VO4催化剂的可见光光催化活性最高。制得的Bi VO4为单斜相,呈分散的、大小均匀的片状,在200~500 nm范围有一个较宽的强吸收平台,具有良好的可见光催化活性,在可见光照射下对浓度为5 mg/L的亚甲基蓝的光催化脱色率达97%以上。
The photocatalyst Bi VO4 was prepared by hydrothermal method using 1-butyl-3-methylimidazolium bromide ([Bmim] Br) ionic liquid. Using high pressure xenon lamp as visible light source and methylene blue as target pollutant, the effects of preparation conditions such as reaction temperature, pH, reaction time and ionic dosage on the visible light activity of Bi VO4 were investigated. The optimum preparation conditions were determined. The crystal phase, morphology and optical properties of the catalyst were characterized by XRD, SEM and UV-Vis diffuse reflectance spectroscopy. The results showed that under the conditions of 2 mL ionic liquid, p H = 4, reaction temperature 180 ℃ and reaction time 4 h, the photocatalytic activity of Bi VO4 was the highest. The obtained Bi VO4 is a monoclinic phase with dispersed and uniform size flakes. It has a broad strong absorption platform in the range of 200-500 nm and has good visible light catalytic activity. Under the visible light irradiation, the concentration is 5 Methylene blue mg / L photocatalytic decolorization rate of more than 97%.