| With the rapid development of human society,it brings many problems such as energy shortage and environmental pollution.It is an urgent problem to find sustainable energy and solve the problem of environmental pollution.Since 1972,Fujishima et al.have found the photocatalytic decomposition of water on the semiconductor TiO2 electrode.The semiconductor catalyst technology has been widely concerned.The semiconductor photocatalyst has been widely used in the treatment of organic and inorganic pollutants,the production of hydrogen from cracking water,and photocatalytic synthesis.However,TiO2 is a semiconductor with wide band gap,which is only in the range of ultraviolet light,and has great limitations in industrial applications.Visible light is an inexhaustible green energy for human beings.A semiconductor which was designed to responding to visible light has become the main research content of researchers.In this case,the emergence of bismuth catalysts has opened a new door for researchers.Among them,Bi203 as the basis of bismuth catalyst has a relatively complete system.Bi2O3 semiconductor catalyst has excellent performance and great potential in the field of photodegradation wastewater.The band gap of Bi203 is narrow,and it can respond in the visible light range.However,the photocharges of Bi2O3 is not easy to separate,because of this characteristic,the photocatalytic activity of Bi2O3 was reduced.Therefore,it is necessary to modify Bi2O3 to improve its photocatalytic activity.Another popular bismuth catalyst are materials of the sillenite family.Materials of the sillenite family have the properties of photorefractive,photoluminescence and photoconductivity,so they have broad application prospects in photoelectricity and have attracted widespread attention.Bi25FeO40 is a material of the sillenite family of iron.Bi25FeO40 powders has no symmetrical center structure and the spatial point group is 123.At the same time,there are a lot of defects in the powders structure,which make Bi25FeO40 powders have a good application prospect in the field of photocatalysis.Based on this,in this paper,Bi203 semiconductor powders was doped and modified to prepare Bi2O3/Ag and Bi2O3/Cu composite powders,and Bi25FeO40 powders was prepared by one pot solvothermal method.The main research contents are as follows:(1)Bi2O3/Ag was synthesized by a simple one-step synthesis method at room temperature and atmospheric pressure.A series of samples were prepared by adjusting the reaction temperature and the ratio of raw materials.The samples were characterized simply and the photocatalytic activity was determined.The results showed that the samples had good photocatalytic activity.The degradation rate of Rhodamine B reached more than 99%in two hours of visible light.(2)Bi203/Cu was synthesized by a simple one-step synthesis method at room temperature and atmospheric pressure,A series of samples were prepared by adjusting the reaction temperature and the ratio of raw materials.The samples were characterized simply and the photocatalytic activity was determined.The results showed that the samples had good photocatalytic activity.The degradation rate of Rhodamine B reached more than 99%in two hours of visible light.(3)Bi25FeO40 was prepared by one pot solvothermal method.The pure phase of Bi25FeO40 powders was prepared by adjusting the reaction time and temperature and characterized by a series of characteristics:the band gap of Bi25FeO40 prepared by UV Vis diffuse reflectance analysis was 2.5ev.The valence of Fe in Bi25FeO40 structure is 3 by X-ray electron spectroscopy.Photocataytic activity of Bi25FeO40 powders was evaluated by the degradation of Rhodamine B solution under visible light.After irradiating for 120 min 99.9%of Rhodamine B was degraded by the Bi25FeO40 powders.This proves that Bi25FeO40 has good photocatalytic performance. |
PDF Full Text Request