Preparation Of Ultrathin Bismuth Oxyhalide Photocatalysts And Their Properties Of Photocatalytic Sterilization

Photon absorption efficiency and carrier separation efficiency are the two most important problems for semiconductor photocatalyst. Numerous studies about modification of the photocatalysts are also developed around these two points. Such as doping, dye sensitization and surface plasmon resonance effect are to increase photon absorption efficiency of the catalysts; Cocatalyst loading is to improve the carrier separation efficiency; Modified with carbon materials and building composite photocatalyst can increase photon absorption efficiency and carrier separation efficiency at the same time. However, the photocatalysts of these methods need to be secondary modified with other chemical agents. Reducing the thickness of two-dimensional crystals to nanometer scale can enhance the defect concentration and internal electric field intensity, thereby increasing photon absorption efficiency and carrier separation efficiency of the photocatalyst. This is an important means to improve the photocatalytic properties of the catalyst, to solve the problem of poor photocatalytic properties for molecular oxygen activation, and to broaden the application areas of photocatalysis.This paper aims to explore the preparation of ultrathin nanostructured VLD BiOX photocatalyst which is stale and promising with low power. The paper systematically introduces the basic meaning and principle of the semiconductor photocatalysis, and the current research of photocatalyst photocatalyst and halogen bismuth oxide photocatalyst. Then the methods to prepare ultrathin bismuth oxyhalide including Bi24O31Cl10, BU-BiOCl and FL-BiOI are described in detaile. Theoretical research on the simulated spacing of the(001) crystal plane, charge density contour, and and total DOS and partial DOS of the prepared materials combing with the characterization of XRD, SEM, TEM, XPS, DRS, PL and so on have been done to research the reaction mechanism, structure and photocatalytic performance of synthesized halogen bismuth oxide materials.The research on the application of ultrathin bismuth oxyhalide photocatalysts in this paper mainly includes three branches: photocatalytic hydrogen production, the photocatalytic reduction CO2 into fuel and the photocatalytic bactericidal properties. Photocatalytic bactericidal experiment is carried out on Escherichia coli(E.coli). The bacteriostatic and bactericidal effect of the catalysts are determined by observing the growth of E. coli under different conditions. The experimental characterization and theoretical calculation results also indicated that expanded facets spacing and oxygen vacancy of as-synthesized BU-BiOCl and FL-BiOI enhanced separation efficiency of photoinduced carriers and photon absorption efficiency. Therefore, BU-BiOCl and FL-BiOI showed higher activity for H2 production under visible light irradiation and for CO2 conversion under visible or near-infrared(NIR) light. The large ratio of surface to thickness results in higher photocatalytic properties of Bi24O31Cl10 for activate molecular oxygen. In addition, the photocatalytic sterilization experiments showed that all of them can effectively kill E. coli.