Direct synthesis of anatase TiO₂ aerogel resistant to high temperature under supercritical ethanol

TiO₂ aerogel (TA) was directly prepared by supercritical ethanol drying of TiO₂ gel which was synthesized by a simple one-step sol-gel process. High temperature of the supercritical ethanol drying led to the decomposition of most of the organic groups in the TiO₂ gel and formation of anatase TiO₂. Thermogravimetric (TG) revealed that the resulting TA was anatase TiO₂ with a small amount of organic groups. X-ray diffraction (XRD), scanning electron microscope (SEM) and N₂ isothermal adsorption/desorption tests indicated that the crystalline structure (crystalline size and phase) and pore structure of TA were very stable after thermal treatment below 700 C.