Acetone Sensing with In2O3-Coated Nb2O5 Nanorod Sensors

Nb2O5-core/In2O3-shell nanorods were synthesized by thermal oxidation of Nb foil followed by sputter deposition of In2O3. The 1D nanostructures exhibited a rod-like morphology with widths and lengths ranging from 20 to 70 nm and 10 to 20 /jm, respectively. The sensing properties of Nb2O5-core/In2O3-shell nanorod sensors toward acetone gas were examined. The pristine Nb2O5 nanorods showed responses ranging from -121 to -253% to CH3COCH3 concentrations of 200-1,000 ppm. In contrast, Nb2O5-core/In2O3-shell nanorods showed responses ranging from -167 to -563% over the same concentration range. These responses are comparable or superior to other metal oxide semiconductor gas sensors in the literature. The underlying mechanism of the enhanced sensing properties of Nb2O5-core/In2O3-shell nanorods toward CH3COCH3 is also discussed.