Photocatalytic Activities of Microcrystalline TiO2 Incorporated in Sheet Silicates of Clay

Article abstract of DOI:10.1021/j100349a031

Photochemical and photocatalytic properties of microcrystalline TiO2 incorporated in the interlayer space of montmorillonite were investigated in reference to those of TiO2 powder particles which were prepared by agglomeration of a titania sol that was used in the preparation of the titania-pillared clay.The pillared TiO2 microcrystallites having ca. 15-Angstroem pillar height showed a ca. 0.58-eV blue shift in its absorption and fluorescence spectra compared with those of the TiO2 particles, exhibiting the quantum size effect.The excited electronic states of the pillared TiO2 were determined to be 0.36 V more negative than that of the TiO2 powder particles.Photocatalytic activities of the pillared TiO2 were greater than those of the TiO2 powder particles for decomposition of 2-propanol to give acetone and hydrogen and of n-carboxylic acids with up to eight carbons (from acetic acid to caprylic acid) to give the corresponding alkanes and carbon dioxide, though the pillared TiO2 exhibited lower activities for decomposition of capric acid, having 10 carbons in a molecule.