Titanium dioxide (TiO2) nanoparticles co-doped with N and Fe were prepared via modified sol-gel process. The products were characterized by transmission electron microscopy (TEM), N-2 adsorption, X-ray diffraction (XRD), Raman spectroscopy, UV-vis spectroscopy, photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS). It is shown that the prepared TiO2 particles were less than 10 nm with narrow particle size distribution. The addition of MCM-41 caused the formation of Ti-O-Si bond which fixed the TiO2 on MCM-41 surface, thus restricted the agglomeration and growth of TiO2 particles. The photocatalytic performance in the degradation of methylene blue showed that N, Fe co-doped TiO2 exhibited much higher photocatalytic activity than doped sample with nitrogen or Fe3+ alone under both UV and visible light. N, Fe co-doping decreased the loss of doping N during the degradation reaction, thus increased the photocatalytic stability. It was also found that the nitridation time had significant influence on the photocatalytic activity of prepared TiO2 catalysts. (C) 2011 Elsevier B. V. All rights reserved.