A NOVEL GRAPHENE / Bi2WO6 COMPOSITE PHOTOCATALYST WITH HIGH ADSORPTIVITY AND THEIR PHOTOACTIVITY

摘要

To utilize solar energy efficiently, the photocatalysts with high visible-light-driven activities are developed to overcome the drawback of the narrow photo-response spectrum of conventional TiO2. Bi2WO6, as a novel visible-light photocatalyst, has been investigated to decompose organic contaminants [1]. To improve the photoactivity of Bi2WO6, hierarchical nest-like structure [2] and hierarchical flowers [3] with a hollow structure were constructed by solution self-assembly of nanoplates. The Bi2WO6 hierarchical structures possessed high surface area and porous structure, which provided a large number of ideal adsorption sites for organic molecules. High photogenerated charge recombination is very harmful to photocatalytic activity of Bi2WO6. To accelerate the charge carrier separation, the "Schottky" barrier between the metal and the semiconducting photocatalyst was considered to be an efficient path to improve the intcrfacial charge transfer process. Bi2WO6/Cu~0 [4] with Fenton-like synergistic effect and Bi2WO6/Ag~0 [51 hclerojunetions were designed to prevent the electron-hole recombination and improve the photocatlytic performance. Very recently, carbon-modified Bi2WO6 [6] was considered to enhance the photoactivity due to high specific surface area and high conductivity of carbon. Graphene is a novel nano-carbon material, which possesses high specific. surface area, high electric conductivity, high light transparency and single atom layer in thickness. In the present work, graphene-modified Bi2WO6 was prepared and its visible-light-driven photo-catalytic performance was studied.