Nanocasting Synthesis of Ultrafine WO3 Nanoparticles for Gas Sensing Applications
1 Materials and Energy Research Center, P.O. Box 14155-4777, Tehran, Iran
2 ME2, Departament d’Electrònica, Universitat de Barcelona, Martí i Franquès, 1, 08028, Barcelona, Spain
Nanoscale Research Letters 2009, 5:370-373 doi:10.1007/s11671-009-9490-8Published: 21 November 2009
Ultrafine WO3 nanoparticles were synthesized by nanocasting route, using mesoporous SiO2 as a template. BET measurements showed a specific surface area of 700 m 2/gr for synthesized SiO2, while after impregnation and template removal, this area was reduced to 43 m 2/gr for WO3 nanoparticles. HRTEM results showed single crystalline nanoparticles with average particle size of about 5 nm possessing a monoclinic structure, which is the favorite crystal structure for gas sensing applications. Gas sensor was fabricated by deposition of WO3 nanoparticles between electrodes via low frequency AC electrophoretic deposition. Gas sensing measurements showed that this material has a high sensitivity to very low concentrations of NO2 at 250°C and 300°C.