Aerogels and how to tailor them for photocatalysis

Abstract

Aerogels are a fascinating and versatile material with high potentials in various application. Within this presentation we will showcase aerogels potentials in aviation, transportation and energy related applications. Besides the classic approaches of silica based materials the focus will be on semiconducting metal oxides such as titania. We will demonstrate that the aerogels properties can be selectively controlled by the respective synthesis parameter. Especially, the direct influence of acid concentration was investigated on. Due to the dependence on the steric hindrance of the alkoxy ligands, the applied chloride ions coordinate in different ways to the used Titania precursor which changes the hydrolysis and condensation reaction kinetics. Also, the usage of different solvents led to a ligand exchange of the Titania precursor which lead to different intermediate complexes with coordinated chloride ions that act as templates for the formation of mixtures of anatase and brookite polymorph with tunable ratios. In-situ analysis methods such as Raman spectroscopy, revealed the polymorph growth during three to seven days of aging in the wet gel state. We will also report on the potentials of these materials in terms of photocatalytic application within a broader scope.