Highly improved visible light photocatalytic activity of BiPO4 through fabricating a novel p-n heterojunction BiOI/BiPO4 nanocomposite

Novel BiOI/BiPO4 photocatalyst with a p-n heterojunction was fabricated via a facile deposition-precipitation method. The phase structures, morphologies and optical properties of the obtained samples were studied by several characterization tools including XRD, SEM, HRTEM, BET, EDS and UV-Vis DRS. BiOI/BiPO4 photocatalyst displayed much higher photocatalytic performance for the methyl orange (MO) degradation than the single BiPO4 and BiOI under visible light (lambda > 400 nm). The best photocatalytic activity of BiOI/BiPO4 with nearly 98% MO degradation located at molar percentage ratio of 40% after 2 h irradiation. Moreover, BiOI/BiPO4 could also decompose 50% of colorless phenol solution after 8 h irradiation. The enhanced photocatalytic performance can be mainly ascribed to the formation of p-n heterojunction interface in BiOI/BiPO4 which facilitates the transfer and separation of photogenerated electron-hole pairs, as well as the strong visible light absorption originating from the sensitization role of BiOI to BiPO4. (C) 2013 Elsevier B.V. All rights reserved.