Fabrication And Photocatalytic Properties Of Zine Oxide And Its Composites

With the high speed development and progress of human civilization,it brings a series of problems,such as resource shortages, environmental pollution, especially the water pollution problems have aroused people's wide attention. Which one of the hot spot of research is the use of Zn O and Ti O2 semiconductor oxide materials as catalyst to catalytic treatment of organic pollutants.Zn O belongs to direct wide bandgap semiconductor materials is directly broadband gap semiconductor materials. The band gap of Zn O is 3.37 e V and the thermodynamic stability of crystal structure is wurtzite structure.Zn O has many characteristics,such as high chemical stability, nontoxic, low cost, easy preparation and high photocatalytic efficiency,etc.It is a new semiconductor material which is widely used in the field of photocatalysis. Nevertheless, the catalytic efficiency of Zn O has some shortcomings, On the one hand, it has a good absorption only in the ultraviolet region of sunlight, can't effectively use the visible light part;On the other hand, the electron-hole pairs of Zn O easily compound, thus reducing the photocatalytic performance.So some composite photocatalytic materials have been successively researched based on Zn O,these materials have a wide optical response range and higher photocatalytic degradation activity.This paper takes Zn O as the research subject, A series of studies are taken to the structure, morphology and properties of the micron grade Zn O and Cu O/Zn O composite powder, the details are as follows:(1)In this work, zinc acetate was used as raw materials and ultrasonic spray pyrolysis method was taken to synthesize Zn O spherical powders. TG-DSC detection was carried out on the precursor which is in order to analyse the thermal decomposition process of zinc nitrate. The experimental results show that it can effectively control the morphology of particles by transforming the resistance furnace temperature and concentration of the precursor solution.The higher reaction temperature is helpful for the synthesis of the Zn O powder of more smooth surface and better sphericity,but the temperature is not too high.The prepared products have larger particle size when the concentration of zinc nitrate solution is increased,the sphericity will also be worse. And adding different additives in the precursor solution will also have obvious effect on the morphology of the sample.(2)With the mixture of zinc nitrate and copper nitrate solution as the precursor solution, the Zn O/Cu O composite hollow spherical particles are successfully prepared using spray pyrolysis technology at 700? of the furnace temperature by changing the copper nitrate compound proportion.The structure, morphology and UV-Vis absorption properties of the composite materials have been characterized by X-ray diffraction, scanning electron microscope,energy dispersive spectroscopy,ultraviolet visible spectrophotometer.The catalytic degradation performance of methyl orange(MO) of the composite photocatalyst is investigated. The experimental results show that: Zn O/Cu O composites have good absorption in the ultraviolet and visible light region, So the absorption range of the spectra is increased significantly. Its photocatalytic activity is higher than the pure Zn O obviously, and the catalytic efficiency of the composite material which composite 5% Cu O is highest.