NEW MESOSTRUCTURED POROUS TIO2 SURFACE PREPARED USING A 2-DIMENSIONALARRAY-BASED TEMPLATE OF SILICA PARTICLES

Mesoporous photocatalytic titanium dioxide films with periodic structu res were prepared by molding from two-dimensionally ordered arrays of monodisperse SiO2 particles. The morphology of the porous structures i n these films was dependent upon the annealing temperature. The photoc atalytic activity of the films was confirmed, as evidenced by the phot odeposition of silver on the textured film surfaces. Attachment of the free-standing films to rigid supports allowed us to locate specific m icroscopic areas at will and to monitor the progress of the silver pho todeposition in these areas using optical. microscopy and scanning ele ctron microscopy, with both secondary electron and backscattered elect ron detection. However, the repeated electron beam exposure in these s elected areas was found to adversely affect the photoreducibility. Alt hough the detailed film morphology did not affect the macroscopic phot ocatalytic activity, we found subtle differences in the silver nucleat ion process which depended upon the pore wall thickness.