Preparation of high surface area titania (TiO2)films and powders using particulate sol-gel route aided by polymeric fugitive agents

作者：Mohammadi M R^*; Cordero Cabrera M C; Fray D J; Ghorbani A

来源：Sensors and Actuators B: Chemical , 2006, 120(1): 86-95.

DOI：10.1016/j.snb.2006.01.046

• films
• sol-gel processes
• specific surface area
• TiO2
• gas sensors

High specific surface area (SSA) nanocrystalline powders and dip-coated TiO2 films have been prepared by particulate sol-gel route aided with polymeric fugitive agents (PFA), namely trehalose dihydrate (THD), polyethylene glycol (PEG6000) and hydroxypropyl cellulose (HPC). Powders obtained without PFA, heat-treated at 160 degrees C show a SSA of 181 m(2)/g, a value that could be increased up to 271 and 223 m(2)/g for samples heat-treated at 300 degrees C when PEG6000 and HPC were used, respectively, whereas SSA of 201 m(2)/g were achieved by using THD and subsequence heat-treating at 500 degrees C. Such surface area is one of the highest reported in the literature under these conditions. Crystallite sizes vary from 1 nm for as-produced powders up to 4 nm for powders heat-treated at 600 degrees C. It was found that crystallite size, microstructure, specific surface area and phase transformation are strongly dependent upon the PFA/TiO2 ratio and annealing temperature. Films produced under optimised conditions showed excellent microstructural properties for gas sensing applications.

• 出版日期2006-12-14