可见光响应型ZnO/Bi_2O_3复相光催化剂的制备及其性能研究

Preparation and Properties of ZnO/Bi_2O_3 Multiphase Photocatalytic Materials Response to Visible Light

以Zn(Ac)2.2H2O和Bi(NO3)3.5H2O为主要原料,采用溶胶-凝胶法成功制备了可见光响应型的高效复相ZnO/Bi2O3催化剂。利用X射线衍射(XRD)、扫描电镜(SEM)对样品进行了表征,并以甲基橙为目标污染物,测试样品的光催化性能,研究了初始合成条件、光源等对样品光催化性能的影响。实验结果表明:在nZn∶nBi为1∶1,浓度为0.05 mol/L条件下制得的凝胶,经600℃煅烧2 h后,样品呈现六方纤锌矿结构的氧化锌晶相并伴有单斜α-Bi2O3、三斜ω-Bi2O3晶相。在16 W紫外灯、500 W卤素灯照射下,2.5 h后,甲基橙的脱色率为95.73%,68.36%,而经太阳光照射2.5 h,甲基橙的脱色率分别为53.8%,但将其继续置于阳台上24 h,脱色率可达97.6%。在16 W紫外灯的辐照下,样品重复使用6次,甲基橙的脱色率仍在90%以上,表明催化剂具有较高的重复使用率。

Using Zn（Ac）12·2H2O and Bi（NO3）3·5H2O as the main raw materials, ZnO/Bi2O3 mLtltiphase photocatalytic materials response to visible light with excellent photocatalytic properties were successfully synthesized by sol-gel method. The as-prepared samples were characterized by XRD and SEM, their photocatalytic activities andreusability were investigated under the conditions of different light source using the methyl orange as a target pollutant. The effects of initial synthesis conditions and light source on photocatalytic prope^es were also studied. The results show that the gel prepared under the condition of a Zn/Bi molar ration of 1：1 and concentration of 0.（15 mol/L were calcined at 600℃ for 2 h , the as-prepared samples show to be compose of wurtzite ZnO, monochnic a-Bi2O3, triclinic ω-Bi2O3. The decolorization rate of methyl orange were 95.73%, 68.36% under irradiation of 16 W UV and 500 W halogen lamp for 2.5 h, however under sunlight, that was only 53.8%, but continue to be placed on the balcony for 24 h, the decolorization rate is up to 97.6%. In addition, the catalyst was reused the sixth times, decolorization rate was still up to 90%, indicating catalyst has a high reusability rate.