Abstract
Titania coated silica aerogels are prepared by supercritical drying of wet gels which are treated by soaking of silica wet gels into a titanium alkoxide solution. The phase of the titania decides the properties of the aerogels (surface area, photocatalytic activity etc.). The effects of the supercritical drying condition on the titania phase were investigated, and it was found that the phase of the titania on silica aerogel became amorphous when the wet gel was supercritically dried at low temperature, but the phase became anatase when it was dried at high temperature (around 500K). Once the aerogels coated by amorphous titania was obtained, the amorphous phase was not cristallized if the aerogel was heated to 900K. Characterization of those aerogels was also carried out.
