Chiang Mai University, Thailand
pp. 199 - 202
Keywords: unloaded and Pt-loaded In2O3 (M = Pt, Nb, Ru), nanoparticles, flame spray pyrolysis (FSP), NO2 gas sensors
Unloaded In2O3 and M-loaded (M = Pt, Nb and Ru) In2O3 nanoparticles loaded with 0.25–1.00wt% metal were successfully synthesized in a single step by the flame spray pyrolysis (FSP) technique. Unloaded In2O3 and M-loaded (M = Pt, Nb and Ru) In2O3 nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM). The BET surface area (SSABET) of the nanoparticles was measured by nitrogen adsorption. X-ray photoelectron spectroscopy (XPS) was employed to characterize the chemical composition and valence state. Gas sensing studies showed that Pt-loaded In2O3 gave an enhancement in NO2 sensing in term of response and selectivity. The optimal loading was found to be 0.5wt% Pt to exhibit a high NO2 response of 1900 towards 5 ppm NO2 in dry air at 250oC. It also exhibited good selectivity against H2S and NO gases. When compared to other metal loading such as Nb and Ru, Pt-loaded In2O3 exhibited much better gas sensing against NO2, H2S and NO gases.