High quality ordered macroporous titania films with large filling fraction

Large-area three-dimensionally ordered macroporous titania films have been fabricated by silica colloidal crystal templating. The matrix was obtained through a dip-infiltrating sol-gel process, with subsequent removal of the silica microspheres by chemical etching. Scanning electron micrograph confirms the ordering of the macroporous structure, and transmission spectra of the crystal show a pronounced attenuation dip which shifts when different solvents are infiltrated. Bragg's law at normal incidence was used to calculate the filling fraction of the titania backbone. (c) 2005 Elsevier B.V All rights reserved.