The important role of tetrahedral Ti4+ sites in the phase transformation and photocatalytic activity of TiO2 nanocomposites

Highly photoactive, tetrahedral Ti4+ sites can be created, other than in zeolite cavities and on silica substrate, in mixed-phase TiO2 nanocomposites. The tetrahedral Ti4+ species was shown to be an intermediate formed during the thermally driven phase transformation from anatase to futile.