Mesoporous structure and phase transition of nanocrystalline TiO2

Mesoporous nano crystalline titanium dioxide with narrow pore size distribution was prepared by a sol-gel technique. Butanediol mixed with tetrapropylothotitanate was used as precursors. The aging time for the synthesis has an evident influence on the phase transition of TiO2 and the nucleation process. A very fine network texture made from uniform nanoparticles was revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The mesoporous structures as-prepared titania were maintained after a heat treatment at 350 and 400degreesC for 1 h, exhibiting a significant thermal stability. Four titania crystal phases (amorphous, anatase, anatase-rutile, rutile) were observed at different calcination temperature. (C) 2002 Published by Elsevier Science B.V.