Using a simple sol-gel method, a novel magnetic photocatalyst was produced by immobilization of TiO2 nano-crystal on Fe-filled carbon nanocapsules (Fe-CNC). High resolution TEM images indicated that the immobilization of TiO2 on Fe-CNC was driven primarily by heterogeneous coagulation, whereas surface nucleation and growth was the dominant mechanism for immobilizing TiO2 on acid-functionalized hollow CNC. The TiO2 immobilized on Fe-CNC exhibited the anatase phase as revealed by the X-ray diffraction (XRD) patterns. In comparison with free TiO2 and TiO2-coated CNC, TiO2-coated Fe-CNC displayed good performance in the removal of NO gas under UV exposure. Due to the advantages of easy recycling and good photocatalytic efficiency, the novel magnetic photocatalyst developed here has potential use in photocatalytic applications for pollution prevention. (c) 2006 Elsevier B.V. All rights reserved.