The visible light efficient W, N co-doped TiO2 photo catalysts are prepared by sol-gel method. New linkages of N, W and O are formed as N-Ti-O, N-W-O, Ti-O-N and W-O-N. Electron paramagnetic resonance illustrates the presence of oxygen vacancies in W, N co-doped TiO2 acting as trapping agencies for electrons to produce active species. X-ray photoelectron spectroscopy confirms the presence of new energy states. New linkages and oxygen vacancies are proved to be the main cause for the improved photo catalytic performances. W, N co-doped TiO2 has new energy states which narrow the band gap effectively. W, N co-doped TiO2 is thermally stable and retains its anatase phase up to 900 degrees C. 4.5% W, N co-doped TiO2 showed superior activity for the degradation of Rhodamine B and 2,4-dichlorophenol as compared to pure titania, Degussa P-25, traditional N-doped TiO2 and pure WO3. (C) 2012 Elsevier Ltd. All rights reserved.