掺铁ZnO光催化氧化甲苯气体研究

Photocatalytic Oxidation of Toluene Gas by Fe-Zn O Catalyst

为了提高光催化剂在可见光下的催化活性,以Zn(NO_3)_2·6H_2O,NH_2CONH_2为原料,采用超声辅助均匀沉淀法制备了Fe^(3+)掺杂ZnO光催化剂(F-ZnO),并用热重(TG-DTA)、X射线衍射(XRD)、扫描电子显微镜(SEM)等对产物进行了表征。研究了超声反应时间、Fe^(3+)的掺杂量、原料配比、焙烧温度、甲苯初始浓度等因素对光催化降解甲苯气体的影响。研究表明,在超声反应时间为1 h,Fe^(3+)掺杂量为0.5%(摩尔分数),M(Zn(NO_3)_2·6H_2O):M(NH_2CONH_2)=1︰2,焙烧温度为450℃条件下制备的催化剂催化活性最佳。当甲苯初始质量浓度为100 mg/m^3,光反应时间为3 h时,可见光下FeZnO对甲苯的降解率可达到84.7%。该催化剂在有机废气治理领域具有潜在的应用价值。

To improve the activity of photocatalytic oxidation under visible light, the Fe^（3＋）doped ZnO（Fe-ZnO） catalysts was prepared by ultrasound-assistant homogeneous precipitation method using zinc nitrate and urea as raw materials. The Fe-ZnO was characterized by X-ray diffraction（XRD）, thermogravimetry（TG） and scanning electron microscopy（SEM） instruments. The effects of the ultrasonic reaction time, the Fe^（3＋）concentration, the ratio of raw materials, calcination temperature, initial concentration of toluene, and photoreaction time on the degradation rate of toluene gas were investigated. Results showed that the optimum conditions for preparation of the best Fe-Zn O catalyst were ： ultrasonic reaction time of 1 h, the Fe^（3＋）concentration of 0.5 mol %, M（Zn（NO_3）_2·6H_2O）︰M（NH_2CONH_2） = 1︰2, the calcination temperature at 450 ℃. Using this catalyst under the visible light, as the the initial concentration of toluene was 100 mg/m^3 and photoreaction time was about 3 h, the degradation rate of toluene was about 84.7%. Fe-Zn O shows a potential application in the treatment of organic waste gas.