BACKGROUNDChlorophenols (CPs) are organic pollutants and are most widespread in the aqueous environment. Photocatalytic degradation of organic compounds has been extensively studied as a potential technology for water treatment. In this study, BiOI/Bi2WO6 hierarchical heterostructure with flower-like morphology was synthesized by a facile method using a one-step hydrothermal approach. The catalytic activities of the photocatalysts were tested by the degradation of 2,4-DCP under visible-light irradiation and the photocatalysis mechanism of BiOI/Bi2WO6 was investigated. RESULTSThe as-prepared catalysts exhibited the characteristic peaks of BiOI and Bi2WO6. The photocatalytic activities, which were evaluated by degradation of 2,4-DCP under visible light irradiation, were enhanced significantly by BiOI/Bi2WO6 hierarchical heterostructures with different molar ratios of BiOI to Bi2WO6. CONCLUSIONSBiOI/Bi2WO6 hierarchical heterostructure significantly enhanced the photocatalytic activity. The optimum percentage of BiOI was 10%. The optimal initial pH value of 2,4-DCP was determined to be pH 8. The possible reaction mechanisms were discussed on the basis of the calculated energy band positions. (c) 2014 Society of Chemical Industry