Preparation Of Zinc Oxide Composites And Their Applications

Along with the development of society, more and more industrial wastewater and domestic sewage influence people’s life and the development of the city, especially the sewage contains difficult to decompose organic matter, seriously affecting water quality, the more to become a big problem in the governance environmental. The wastewater and domestic sewage are solved of physical and chemical methods. Physical methods mainly through the process of adsorption of the water contained in the organic dye adsorption, the disadvantage is a long time, and low efficiency. Through chemical degradation of organic matter in sewage has increasingly become the focus of the study, especially after the excellent performance of the semiconductor material it is widely understood that the use of photocatalytic degradation of organic pollutants in water has become a hot topic, as is a simple, no secondary pollution, low cost, has been more and more attention.Zinc oxide with broadband gap, strong oxidation ability and the advantages of good stability. It widely used in photocatalytic. Based on photocatalytic mechanism, the main factors affecting photocatalytic that the catalyst, the light absorption and electron-hole pair recombination. This paper mainly focus on the preparation and performance of different zinc oxide composites, in order to reduce the electron-hole pair recombination, thereby improving the efficiency of photocatalytic degradation. The main contentsof the thesis is summarized as follows:1. ZnO-reduce graphene oxide (RGO) composites were synthesized via hydrothermal method for photocatalysis. The RGO act as an excellent electron-acceptor/transport material and hinder electron-hole pair recombination to improve the efficiency of photocatalytic degration. ZnO-RGO composites fabricated by hydrothermal method with 3.0 wt.% achieve the best photocatalytic efficiency of 90% under the UV light irradiation. While pure ZnO photocatalytic efficiency of only 77.8% under the same condition.2. ZnO-Au composites were synthesized via the deposition-precipitation method for the photocatalytic degradation of organic dyes. The Au act as an excellent electron-acceptor/transport material and hinder electron-hole pair recombination to improve the efficiency of photocatalytic degration. ZnO-Au composites fabricated by the deposition-precipitation method with 5.0 wt.% achieve the best photocatalytic efficiency of 80% under the UV light irradiation. While pure ZnO photocatalytic efficiency of only 56% under the same condition.3. The eighth of Zeolitic imidazolate frameworks (ZIF-8) were synthesized via the seeded method. Then as-prepared ZIF-8 was annealed to obtain the ZnO for photocatalytic degradation of organic dyes. The ZnO act as an excellent of morphology and adsorption materials. When the annealing temperature is 600℃, the optimum photocatalytic effect, photocatalytic efficiency of 100%, while the photocatalytic effect of ZnO 800℃ annealed only 82% under the UV light irradition.