Zhu Xiaodong, Wang Juan, Yang Daixiong, Liu Jiawei, He Lili, Tang Mao, Feng Wei, Wu Xiaoqiang
College of Mechanical Engineering, Chengdu University Chengdu 610106 China
RSC Adv. 2021 Aug 10;11(44):27257-27266. doi: 10.1039/d1ra05060e. eCollection 2021 Aug 9.
Pure ZnO and Ag-ZnO nanocomposites were fabricated a sol-gel route, and the obtained photocatalysts were characterized by XRD, SEM, TEM, BET, XPS, PL and DRS. The results showed that Ag nanoparticles deposit on the ZnO surface and Ag modification has negligible impact on the crystal structure, surface hydroxyl group content and surface area of ZnO. However, the recombination of photogenerated electrons and holes was suppressed effectively by Ag loading. The photocatalytic activity was investigated by evaluating the degradation of MB under xenon lamp irradiation as the UV-visible light source, and the results show that the photocatalytic activity of ZnO significantly improved after Ag modification. Ag-ZnO photocatalysts exhibit higher photocatalytic activity than commercial photocatalyst P25. The degradation degree of MB for 1%Ag-ZnO was 97.1% after 15 min. ˙O radicals are the main active species responsible for the photodegradation process, and Ag-ZnO heterojunctions generate more ˙O radicals, which is the primary reason for the improved photocatalytic performance.
通过溶胶-凝胶法制备了纯ZnO和Ag-ZnO纳米复合材料，并用XRD、SEM、TEM、BET、XPS、PL和DRS对所得光催化剂进行了表征。结果表明，Ag纳米颗粒沉积在ZnO表面，Ag改性对ZnO的晶体结构、表面羟基含量和表面积影响可忽略不计。然而，通过负载Ag有效地抑制了光生电子和空穴的复合。以氙灯作为紫外-可见光源，通过评估亚甲基蓝（MB）的降解来研究光催化活性，结果表明，Ag改性后ZnO的光催化活性显著提高。Ag-ZnO光催化剂表现出比商业光催化剂P25更高的光催化活性。15分钟后，1%Ag-ZnO对MB的降解率为97.1%。˙O自由基是负责光降解过程的主要活性物种，Ag-ZnO异质结产生更多的˙O自由基，这是光催化性能提高的主要原因。
