Novel BiOI/BiOBr heterojunction photocatalysts with enhanced visible light photocatalytic properties

A novel heterojunction photocatalyst BiOI/BiOBr was synthesized by a simple modified deposition-precipitation method. Several characterization tools including XRD, SEM, HRTEM and UV-vis DRS were employed to study the phase structures, morphologies and optical properties of the samples. BiOI/BiOBr exhibited higher photocatalytic activity than single BiOI and BiOBr for the degradation of methyl orange (MO) under visible light (lambda>420 nm). This result can be due to the formation of the heterojunction between BiOI and BiOBr, which can separate photogenerated carriers efficiently. The photocatalytic mechanism study demonstrates that center dot O(2)(-) and h(+) are the main reactive species while center dot OH can be negligible. (C) 2011 Elsevier B.V. All rights reserved.