水热法制备Mn掺杂ZnO及其光催化性能研究

Preparation and Photocatalytic Properties of Mn doped ZnO byHydrothermal Method

ZnO是一类具有广阔应用前景的光催化材料,但是光生载流子复合率高等问题限制了其进一步应用。本研究使用水热法制备了Mn掺杂ZnO粉体,测试了该粉体的物相组成、孔隙结构、发光性质和光催化性能。结果表明,当Mn替代0.5%Zn时,Mn占据了ZnO晶格中Zn的位置,粉体粒度小、比表面积大,抑制了光生载流子的复合,降低了禁带宽度,拓宽了光的响应范围。在8 W、365 nm紫外光条件下光照70 min后,制备的Mn 0.05 Zn 0.95 O粉体对刚果红降解率达到了97.4%,COD去除率达到了76.34%;Mn 0.05 Zn 0.95 O对罗丹明B吸附最好,对亚甲基蓝降解最好;对刚果红连续降解4个循环后,降解率降低了6.6%。该研究成果为光催化降解有机废水提供了技术支撑。

ZnO is a kind of photocatalytic materials with a broad application prospect,but problems such as high carrier recombination rate limit its further application.Mn doped ZnO powders were prepared by hydrothermal synthesis.The phase composition,pore structure,luminescence property and photocatalytic properties were studied.Results show that when Mn is instead of 0.5%Zn in ZnO,Mn occupies the place of Zn in ZnO lattice.The powders have small particle size and large specific surface area.The carrier recombination is inhibited,the band gap is reduced,and the light response range is broadened.Under the condition of 8 W,365 nm UV light,the degradation rate and COD removal of Mn 0.05 Zn 0.95 O powders over Congo red reach 97.4%and 76.34%,repectively,after 70 min irradiation.Mn 0.05 Zn 0.95 O has the best adsorption for rhodamine B,and the best degradation for methylene blue.The degradation rate over Congo red reduces by 6.6%after 4 successive cycles.The results provide technologic support for photocatalytic degradation of organic waste water.