A study was conducted to compare the effectiveness of direct current magnetron sputtered (DC-MS) titanium dioxide films with commercially available Degussa P25 titanium dioxide (powder and dip coated films) for the photocatalytic degradation of organic compounds. DC-MS films were sputtered on glass slides using a titanium target. After four hours heat treatment at 500^oC a dense photocatalytically active anatase structure was obtained. Methylene blue at concentrations from 25 to 50 mgL^-1 was selected as the model organic compound and the reaction was carried out with UV light supplied by a 254nm low pressure mercury lamp, with and without hydrogen peroxide. Methylene blue concentration was determined by UV/Vis spectrometry and intermediates were characterised by total organic carbon (TOC) analysis and high performance liquid chromatography (HPLC).

When used under the same conditions with hydrogen peroxide, it was found that the DC-MS titanium dioxide films where more photocatalytically active than the powder P25 in relation to surface area. Without hydrogen peroxide, negligible degradation of methylene blue was observed with the DC-MS film. This could be due to a long radical induction period most likely attributable to the low surface area of the film. TOC analysis showed that all films catalysed the mineralisation of methylene blue and the major reaction intermediates from this have been identified by HPLC. Scanning electron microscope images of the DC-MS films before and after reaction showed no microstructural changes or surface depositions, indicating that the films are stable to repeated use.