纳米氧化锌的掺杂改性及其光催化应用

A Research on Doping Modification and Photocatalytic Capability of Nano ZnO

以商洛某铅锌尾矿库的铅锌冶金炉窑渣制得的醋酸锌为锌源,尿素为沉淀剂,采用金属离子掺杂的方法制备掺杂金属离子的ZnO粉体。以水体中亚甲基蓝(MB)的光催化脱色降解为模型反应,对各掺杂样品掺杂配比进行优化,考察了光源条件对各掺杂ZnO光催化活性的影响,并对ZnO循环使用的光催化稳定性进行测试。研究表明:掺杂Sn、Ag、Al元素的纳米ZnO,在Sn、Ag、Al与Zn配比分别为1:9、1:40、1:20时,各掺杂样品的催化活性较高。在模拟可见光照射下,各掺杂ZnO样品较纯ZnO对可见光的吸收有一定的增强,在可见光下降解180 min后,相应MB溶液的降解率分别达70.8%、64.8%和53.0%。通过循环测试发现,掺Sn氧化锌样品循环使用3次后,其光降解率仍在95%以上,循环5次时,其光解率仍高于90%。

ZnO nanoparticles were synthesized by doping metal ions and using concentrated carbamide and zinc acetate prepared by the leaching residue of a certain lead-zinc tailings in Shangluo. Deeolorizing of MB dye solution as the model reaction, the doping ratio of the as-made samples was optimized, the effect of lighting conditions tO the decolorizing reaction and the photocatalytic stability of ZnO recycled was examined. Results showed that optimal doping ratio of ZnO doped Sn,Ag,A1 were separately 1：9,1：40.1：20, then all samples had the higher photocatalytic activity. When the zinc oxide dopped Sn,Ag,AI were used as the photocatalyst by UV irradiation time for 100min,the degradation rate of MB is up to 93.6%,99.7%,90.4% respectively, which was significantly increased than the 78.3% when the pure ZnO was used as the photoeatalyst. Under the simulated visible light, the absorptions of all doped samples was stronger than the pure ZnO, the degradation rate of MB is up to 70.8%,64.8%,53.0% respectively after being illuminated for 180min under visible light. By cycling test, the decolorizing efficiency of the MB solution reached above 95% when ZnO doped Sn through three times circulation was as the photocatalyst.It still reached above 90% after five times circulation.