Preparation And Photocatalytic Performance Research Of BiOCl Materials

With the development of industry, environmental pollution which is being more and more serious has been a threat to people’s health. Therefore, how to take care of environmental pollution via efficient methods has attracted much attention in the term of the world. Generally speaking, both physical and chemical methods can be used to treat organic pollutants. As a chemical method, semiconductor photochemical catalytic technique has the highest potential in the degradation of organic pollutants in water for their advantages of high efficiency, no secondary pollution. BiOCl has excellent photocatalytic properties under conditions of UV light, and it is a new type of nano-photocatalytic semiconductor material. However, some disadvantages such as low utilization rates of visible light and poor morphology controllability still exist in BiOCl. How to solve these problems has become the key to the industrial application as bismuth oxide materials. In view of the above shortcomings, the research contents about this paper includes:1. Obtain a kind of BiOCl with a controlled morphology by changing the preparation conditions. In this article, BiOCl were prepared by solvothermal method and low temperature water bath method. The morphology and the photocatalytic properties of BiOCl were adjusted and improved by changing the technological parameters. Choosing the methyl orange as the photocatalytic degradation indicator, ultraviolet light as light resource, the capability of catalyst was evaluated by the decolor rates of methyl orange. The BiOCl prepared by solvothermal method（160℃,12h） is a spherical structure which is composed of many nanosheets and the methyl orange solution was degraded up to 97.88% under UV irradiation for 30 minutes. The BiOCl prepared of low temperature water bath method（80℃,3h） is flower-like composed by many nanosheets. The addition of citric acid has a significant influence on the crystal growth and self assembly process of sample: the methyl orange solution was degraded uo to 100% under UV irradiation for 30 minutes when the molar mass ratio of citric acid and Bi3+ is 1.2. Improve the photocatalytic performance of BiOCl by doping graphene. Graphene oxide was prepared by traditional Hummers method. Using citric acid as a reducing agent to reduce graphene oxide partially under solvothermal conditions. BiOCl / GR nanocomposites have been successfully synthesized based on the successful preparation of BiOCl using solvent thermal method. The addition of graphene destroys the BiOCl globular structure, but improves the photocatalytic property of the samples. After 30 minutes UV irradiation, the photocatalytic efficiency of composites is 99.94% when the mass rate of graphene and BiOCl is 2%. Under 30 minutes simulated sunlight irradiation, the photocatalytic efficiency can reach 99.6% when the mass ratio of graphene and BiOCl is 3%.3. We prepared BiOCl_xBr_1-x composites and investigate its photocatalytic performance. Study the photocatalytic performance and morphology of BiOCl_xBr_1-x composite materials by means of different bromine source: hexadecyl trimethylammonium bromide（CTAB） and potassium bromide（KBr）. Since organic bromine source can form a template by self-assembly, the BiOCl_xBr_1-x which used cetyl trimethylammonium bromide（CTAB） as the surfactant and bromine source has sphere-like shapes and large specific surface area. Besides, the methyl orange solution was degraded by 98.66% after 30 min UV irradiation. The BiOCl_xBr_1-x composites which used potassium bromide（KBr） as a bromine source is formed by the close packing of the nanosheets, the specific surface area is smaller, and the photocatalytic performance is lower than the BiOCl_xBr_1-x which is synthesized by the CTAB as a bromine source.