The zeta-Bi2O3/Bi2MoO6 composites were synthesized by a one-pot template-free hydrothermal method, and were systematically characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, and Raman spectroscopy. Based on the results of 2,4-dinitrophenol (2,4-DNP) degradation under simulated solar or visible light irradiation over the as-prepared materials, it is found that photocatalytic efficiency is closely related to the compositions of the materials, and the 20%zeta-Bi2O3/Bi2MoO6 catalyst performs the best. With the addition of H2O2 (5.0 mmol/L), there is marked improvement of photocatalytic activity. Related mechanisms for the photocatalytic degradation of 2,4-DNP and photocatalytic enhancement of the zeta-Bi2O3/Bi2MoO6 composites have been put forward. (C) 2014 Elsevier B.V. All rights reserved.