Photocatalyst BiOCl modified by polyaniline (PANI/BiOCl) was synthesized via a facile chemisorptions method. X-ray diffraction (XRD), Scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy (DRS) were employed to study the phase structure, morphology and optical properties of the samples. The results showed that the PANI increased absorption intensity and absorption bands of the pure BiOCl. Photodegradation of methyl orange (MO) on the samples were investigated under visible light irradiation and 7 wt.% PANI/BiOCl composite showed the highest photocatalytic activity. The enhanced photocatalytic performance could be attributed to PANI/BiOCl composites and the synergistic effect between PANI and BiOCl. According to experimental results, the possible photocatalytic mechanism of the PANI/BiOCl photocatalysts was proposed. (c) 2013 Elsevier B.V. All rights reserved.