| TiO2 has excellent photocatalytic performance as a n-type semiconductor material. Nano TiO2,because of its non-toxic,harmless,good chemical stability and excellent photocatalytic activity, is in a wide range of applications of wastewater treatment, air purification and the sterilization as a new type of functional nano material of environmental protection. But nano-TiO2 is easily to aggregate and difficult to recycle in the preparation and application, which restrict its actual photocatalytic application seriously. The problem can be effectively solved by finding a right carrier for TiO2. In addition, the low visible-light using efficiency of pure nano TiO2 due to its wide band gap is another reason for limiting the application. The metallic doping,non-metallic doping and codoping to TiO2 can effectively reduce the forbidden band width of TiO2 so as to show an response to the visible light and improve the using efficiency of sunlight.In this paper, composite photocatalyst was prepared by the sol-gel process using Microcrystal Muscovite(MCM) as the supporter, tetrabutyl titanate as the titanic source and copper nitrate as the doping ions. The influence factors of synthesis and the photocatalytic performance of the photocatalyst aiming at the methylene blue solution degradation were studied. The composites were characterized by modern advanced analysis methods such as X-ray diffraction, scanning electron microscope, thermal analysis et al. The Cu2+-doped TiO2/MCM Composites can be obtained with high purity and good crystallinity. The n-TiO2 is the anatase phase. The diffraction peak intensities enhance with the increasing of calcination temperature and holding time, also the grain size increases. Instead, temperature too high and roasting time too long can transform TiO2 from anatase to rutile. Cu2+ ions doped Ti O2 can cause crystal structure changes and diffraction peak shifts. And through uv-vis analysis, it is concluded that the Cu2+-doped widened TiO2 light response range, and caused the red shift of absorption band; during the preparation of the material, the amount of nano TiO2 loaded at MCM surface increases with the amount of the tetranbutyl titanate. TiO2 nanoparticles loaded at MCM surface may be present in the form of a multi-layer structure.By the photocatalytic degradation of Methylene Blue and synthesis parameters optimization, the optimum preparation conditions of Cu2+-doped TiO2/MCM were 500 oC holding 2h, Cu2+ ion doping amount of 5%(Cu2+/Ti4+ molar ratio), muscovite loading of 50%(TiO2/the total mass ratio), the samples for 100 mL at a concentration of 5 mg/L Methylene Blue solution have good photocatalytic properties. Its performance are much better than a single TiO2. Compared with the n-Ti O2 pure, its photocatalytic degradation rate for methylene blue improved from 76% to 97%. Instead, the size of MCM can affect the amount of TiO2 loading so that the photocatalytic efficiency changes. The degradation rate of Methylene Blue rises with reducing particle size of MCM. Furthermore, the MCM was modified with LiNO3, HDTMA·Br by the method of ion exchange, the Li+, HDTMA+ were introduced into interlayer region of MCM and make the interlayer distance increased from 0.99543 nm to 1.60235 nm. And this successfully improve the adsorption properties of MCM and the photocatalytic properties of Cu2+-doped TiO2/MCM composite. |
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