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通过简单、快速的两步法成功制得了一系列不同摩尔比的球形TiO_2-ZnO复合纳米颗粒。用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)及紫外-可见漫反射光谱(UV-vis DRS)等多种手段对产物进行表征。研究发现,TiO_2-ZnO复合物中TiO_2和ZnO两相独立存在;颗粒粒径并非随TiO_2与ZnO摩尔比的提高单调减小,而是先减小后增大;与纯ZnO相比,TiO_2-ZnO复合物的吸收边带发生了明显红移。以甲基橙(MO)和亚甲基蓝(MB)为降解对象,考察了紫外-可见光照下所制TiO_2-ZnO复合纳米颗粒的光催化效果。实验结果显示,所有TiO_2-ZnO复合纳米颗粒均具有较纯ZnO更高的光催化活性。TiO_2与ZnO的摩尔比为0.75∶1时,复合物光催化降解甲基橙的效果最好,TiO_2与ZnO的摩尔比为1∶1时,复合物光催化降解亚甲基蓝的效果最好。
A series of spherical TiO 2 -ZnO nanoparticles with different mole ratios were successfully prepared by a simple and rapid two-step method. The products were characterized by XRD, FESEM and UV-vis DRS. It is found that TiO 2 -ZnO 2 phase exists independently in TiO 2 -ZnO 2 composite. The particle size does not decrease monotonically with the increase of molar ratio of TiO 2 to ZnO, but decreases first and then increases. Compared with pure ZnO, The absorption bandgap of ZnO complex shifted significantly. Methyl orange (MO) and methylene blue (MB) were used as degradation targets to investigate the photocatalytic activity of TiO 2 -ZnO nanoparticles prepared under ultraviolet-visible light irradiation. The experimental results show that all TiO 2 -ZnO nanoparticles have higher photocatalytic activity than pure ZnO. When the molar ratio of TiO 2 and ZnO is 0.75:1, the photocatalytic degradation of methyl orange is the best. When the molar ratio of TiO 2 to ZnO is 1: 1, the photocatalytic degradation of methylene blue is the best.