Ternary Ag/AgCl/BiOIO3 composite photocatalysts are prepared by a facile method. Enhanced visible-light absorption and charge carrier separation are achieved after the introduction of Ag/AgCl particles into BiOIO3 systems, as revealed by ultraviolet-visible diffuse-reflectance spectrometry, photocurrent response and electrochemical impedance spectroscopy. The Ag/AgCl/BiOIO3 composites are applied to the visible-light photocatalytic oxidization of NO in air and exhibit an enhanced activity for NO removal in comparison with Ag/AgCl and pure BiOIO3. A possible photocatalytic mechanism for Ag/AgCl/BiOIO3 is proposed, which is related to the surface plasmon resonance effects of Ag metal and the effective carrier separation ability of BiOIO3. This work provides insight into the design and preparation of BiOIO3-based materials with enhanced visible-light photocatalysis ability. © 2015, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.