**4. Conclusions**

TiO2 thin films which were photocatalytically active were deposited using a non-aqueous modified sol gel method with the addition of two Tween® type surfactants at different concentrations. The addition of surfactant was found to reduce the photocatalytic half-life of the reazurin dye from 16.5 to 3 min for a sample deposited from a sol that contained Tween® 40 or 20 surfactant in a concentration of 3 × 10<sup>í</sup><sup>4</sup> mol·dm<sup>í</sup><sup>3</sup> . The improved photocatalytic activity is attributed to the angular shape of particles, as well as a smaller average particle size range and increased root mean square surface roughness, indicating a greater surface area for catalysis to occur upon.
