Preparation，Modification And Properties Of Bismuth Composite Oxide One-dimensional Hollow Superstructure Materials

The degradation of the natural environment is increasingly serious in themodern societies. Photocatalytic which offers a “green” technology for completelyeliminating contaminants using solar energy has become more popular. In order toeffectively utilize solar energy in photocatalytic processes, the development ofvisible-light-driven photocatalysts to substitute TiO₂has attracted a tremendousamount of attention. Bi-containing oxides, such as Bi₂WO₆, Bi₂MoO₆and BiVO₄,have proven especially promising under visible light irradiation. The morphologyand size controlled synthesis of Bi₂WO₆, Bi₂MoO₆and BiVO₄and theirphotocatalytic properties under simulated sunlight irradiation are necessary due totheir unique chemical and physical properties that are relevant to the shape and size.Thus, we present a facile “sacrificial template” method to fabricate1D Bi₂WO₆hollow superstructures, and extend to other technically relevant bismuth oxides,such as Bi₂MoO₆and BiVO₄. At the same time, through the formation ofTiO₂/Bi₂WO₆composites to further enhance the1D Bi₂WO₆hollow superstructures’photocatalytic activities. The specific work is as follows:Firstly,1D Bi₂WO₆hollow superstructures were fabricated through “sacrificialtemplate” method. The effects of adding sequence, ethanol content and pH on themorphology of1D Bi₂WO₆hollow superstructures are also investigated. Theformation of1D Bi₂WO₆hollow superstructures is due to nanoscale Kirkendalleffect. Furthermore, the current route is more general use, such as1D Bi₂MoO₆andBiVO₄superstructures. Moreover, the photodegradation of RhB is employed toevaluate the photocatalytic activities of the1D Bi₂WO₆hollow superstructuresunder simulated sunlight irradiation. It is demonstrated that the1D hierarchicalrod-like Bi₂WO₆hollow superstructures show superior photocatalytic activities thanthat of P25under simulated sunlight irradiation.Secondly, TiO₂/Bi₂WO₆composites were fabricated through hydrothermalmethods. The effects of solvent, TiO₂content on the morphology of TiO₂/Bi₂WO₆composites are also investigated. Moreover, the photodegradation of RhB isemployed to evaluate the photocatalytic activities of the TiO₂/Bi₂WO₆compositesunder simulated sunlight irradiation. It is demonstrated that the TiO₂/Bi₂WO₆composites show the highest photocatalytic activities among the TiO₂,1D Bi₂WO₆hollow superstructures and the mixture of TiO₂and Bi₂WO₆, the photocatalyticactivities of the TiO₂/Bi₂WO₆composites increased dramatically. Importantly, theTiO₂/Bi₂WO₆composites can easily be separated for reuse and maintaining high photocatalytic activity.