`The article reports on correlations between the process parameters of reactive pulsed dc magnetron sputtering, physical properties and the photocatalytic activity (PCA) of TiO2 films sputtered at substrate surface temperature T-surf <= 180 degrees C. Films were deposited using a dual magnetron system equipped with Ti (phi 50 mm) targets in Ar + O-2 atmosphere in oxide mode of sputtering. The TiO2 films with highly photoactive anatase phase were prepared without a post-deposition thermal annealing. The decomposition rate of the acid orange 7 (AO7) solution during the photoactivation of the TiO2 film with UV light was used for characterization of the film PCA. It was found that (i) the partial pressure of oxygen p(O2) and the total sputtering gas pressure p(T) are the key deposition parameters influencing the TiO2 film phase composition that directly affects its PCA, (ii) the structure of sputtered TiO2 films varies along the growth direction from the film/substrate interface to the film surface, (iii) similar to 500 nm thick anatase TiO2 films with high PCA were prepared and (iv) the structure of sputtered TiO2 films is not affected by the substrate surface temperature T-surf when T-surf < 180 degrees C. The interruption of the sputtering process and deposition in long (tens of minutes) pulses alternating with cooling pauses has no effect on the structure and the PCA of TiO2 films and results in a decrease of maximum value of T-surf necessary for the creation of nanocrystalline nc-TiO2 film. It was demonstrated that crystalline TiO2 films with high PCA can be sputtered at T-surf <= 130 degrees C. Based on obtained results a phase zone model of TiO2 films was developed. (C) 2007 Elsevier B.V. All rights reserved.