Abstract
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Sb2O5 modified porous SnO2 nanocomposites have been synthesized and exhibited superior sensing performances for NO2 detection attributing to the hybrid of p-type Sb2O5 with n-type SnO2 to form p-n junctions.
The Sb2O5 modified SnO2 porous nanocomposites serving as NO2 gas sensing material have been successfully synthesized through a facile hydrothermal method followed by a calcination process. The porous Sb2O5/SnO2 nanocomposites display a dominant pore size of ca. 20nm and specific surface area of 37.2m2g−1, which can provide large contact area for the chemical adsorption of NO2 molecules and abundant channels for the import and export of NO2 gas. Gas sensing tests demonstrated that the as-prepared porous Sb2O5/SnO2 nanocomposites (1mol% Sb2O5) achieved superior sensing performances including high selectivity to NO2, low optimal operating temperature (ca. 100°C), high response (800–5 ppm NO2), and short response and recovery times (20 s and 70 s to 5ppm NO2, respectively). Comparing with pure SnO2 porous structure, the enhanced gas sensing performances of the porous Sb2O5/SnO2 nanocomposites are mainly ascribed to the p-n junctions generated from the hybrid of n-type SnO2 with p-type Sb2O5, which not only improved the response and selectivity to NO2 gas, but also reduced the operating temperature.
