Improved photocatalytic performance of rutile TiO2

The photocatalytic degradation of the model compound methylene blue (MB) was used to monitor the photocatalytic performance of a sequence of undoped rutile TiO2 dispersions, processed under different conditions. In particular two types of powders - strongly reduced (BET = 1.69 m(2)/g) and strongly oxidised (BET = 0.75 m(2)/g) - were processed at 1273 K in a controlled oxygen atmosphere of p(O-2) = 10(-10) Pa and p(O-2) = 75 kPa, respectively. Results demonstrate that the coupling of equal amounts of the strongly reduced and the strongly oxidised rutile TiO2 powders enhances the photo-degradation of MB. This is the first time that the photocatalytic performance of rutile TiO2 has been enhanced through homogeneous coupling. The performance was further enhanced by the addition of an Fe2+ ion redox mediator. All results were compared to a commercial anatase TiO2 powder purchased from Millenium Chemicals (GP350; BET = 121.9 m(2)/g). (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim