Abstract
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 °C show a SSA of 181 m2/g, a value that could be increased up to 271 and 223 m2/g for samples heat-treated at 300 °C when PEG6000 and HPC were used, respectively, whereas SSA of 201 m2/g were achieved by using THD and subsequence heat-treating at 500 °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 °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.
Original language | English |
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Pages (from-to) | 86-95 |
Number of pages | 10 |
Journal | Sensors and Actuators, B: Chemical |
Volume | 120 |
Issue number | 1 |
DOIs | |
Publication status | Published - 14 Dec 2006 |
Keywords
- Films
- Gas sensors
- Sol-gel processes
- Specific surface area
- TiO
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry