Preparation of monolithic titania aerogels with high surface area by a sol–gel process combined surface modification

Abstract

Monolithic titania (TiO₂) aerogels with high surface area were successfully synthesized by the sol–gel process combined surface modification, followed by ambient pressure drying to remove the solvents from the gels. The effects of surface modification used polyethylene glycol (PEG) 2000 as surfactant on the gelation and microstructure of the aerogel were studied in detail. The resultant aerogel with the PEG 2000:TBOT (molar ratio) of 0.005 exhibits specific surface area as high as 495 m² g⁻¹, apparent density of 0.716 g cm⁻³ and porosity of 81.6%. The crystallization of aerogels after heat-treatment does not spoil the monolithic shape and morphology of the aerogel basically, and the specific surface area still keeps a relatively high value of 209 m² g⁻¹. The facile route provides a low-cost strategy for the preparation of metal oxide aerogels with high surface area.