The nature of the active sites of titanium oxide photocatalysts stabilizedon an active carbon surface. A theoretical ab initio study

Ab initio quantum chemical studies at the HF/Lan12dz level of theory were p erformed for two different cluster models representing a graphite surface a nd their interactions with dihydrogen, water, and four-coordinated titanium oxide. Both associative and dissociative channels of their interaction wit h the specific active sites on graphite were considered. Based on the resul ts of these calculations, it was suggested that active sites for the titani um oxides on active carbon can be represented by the OTi(OH)(3) Fragment fo rmed through the dehydroxylation of the surface OH-groups by the four-coord inated titanium oxide species. (C) 2000 Published by Elsevier Science B.V.