Zinc-based Study On Preparation, Characterization And Properties Of Photocatalysts

As a n-type semiconductor, ZnO has a high photocatalytic activity,stable performance, low prices and no secondary pollution. But in the course of a single semiconductor photocatalyst material in the photo-generated electron-hole easily composite, thereby reducing the quantum efficiency of the photocatalyst. If photocatalytic efficiency of ZnO is improved, it will have a very good application prospects. The semiconductor composite is a modified effective way; it utilizes two or more semiconductor which has complementary to nature to improve the catalyst activity. In this paper, the study of the target is the composite of a new compound semiconductor photocatalyst. And explore an effective way to improve the semiconducting photocatalytic performance. The Specific research contents are as follows:(1)First, compound the precursor of light catalyst under the conditions of room temperature, and the precursor is thermally decomposed to obtain the p-n junction type NiO/ZnO photocatalyst. As raw materials with Zn (NO3)2·6H2O, Ni (NO3)2·6H2O and NaOH. Consider Reactive Brilliant Blue as a dye wastewater and analysis the photocatalytic activity of the catalyst. X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet visible diffuse reflectance absorption spectra (UV-Vis DRS) were employed to characterize the as-synthesized samples. Investigation the effect of preparation conditions on photocatalytic performance. Through the optimization of synthesis technology of optical catalyst received the best preparation parameters:the ratio of Ni/Zn is2:1, Ni/Zn ratio is2:1, calcinations’temperature is400℃, and Burning time is1h.(2) Ni/ZnO catalysts were prepared by hydrothermal method. Consider Reactive Brilliant Blue as a dye wastewater and analysis the photocatalytic activity of the catalyst. Its nature and structure were characterized by XRD, SEM, UV-Vis DRS. This results of XRD showed that Zn gradually into ZnO under the hydrothermal conditions. These results showed that the best reaction conditions was:the proportion of the doped nickel nitrate was5%,1the temperature of the water heat was80℃, the hydrothermal time was2h.The introduction of the doping material Changed the morphology of the catalyst and improved the ability of the catalyst degradation.(3) g-C3N4was compound by the polycondensation reaction of melamine. According to the different proportions, g-C3N4was added to the zinc oxide precursor. By heating decomposed could we get g-C3N4/ZnO. Consider Reactive Brilliant Blue as a dye wastewater and analysis the photocatalytic activity of the catalyst. The structure and morphology of the characteristics of the catalyst were characterized by XRD, SEM, XPS, UV-Vis DRS. The results show that when the g-C3N4doping amount is0.5%,the degradation was better. By the analysis of XPS can be further determined to exist in the form.In summary, the successful preparation of NiO/ZnO made it possible to compound the P-N-type semiconductor. The preparation of Ni/ZnO made it possible to compound the doping of metal-semiconductor. The compound of NiO/ZnO is effectively improved the catalytic activity of catalyst.