MORPHOLOGY AND PHOTOCATALYTIC ACTIVITY OF TIO2 AEROGELS

In this paper we describe a methodology to form a data base that will allow us to investigate the correlation between the morphology of TiO2 aerogels and their photocatalytic activity with respect to photodecom position of a water soluble organic compound. We start with a qualitat ive theoretical argument in which we show that any functionality that involves optimization of different length scale should require some ki nd of ramified structure. For photocatalytic activity we need to optim ize substrate and light absorptions with diffusion of products and rea ctants. We proceed to describe the techniques that we use to analyze a nd parametrize the morphology of the aerogels, using nitrogen adsorpti on and Small Angle Neutron Scattering. The photocatalytic activity is monitored through the photodecomposition of salicylic acid. We compare the adsorption and photodegradation of salicylic acid on the aerogels to many other forms of TiO2 and report that under our experimental co nditions the photocatalytic activity of the aerogels is superior.