In2O3-SnO2 Hedgehog-Like nanostructured heterojunction for acetone detection

The In2O3-SnO2 heterojunction nanostructures resembling hedgehogs were synthesized through hydrothermal method and physical stirring for acetone detection. SEM and TEM characterization showed that the composites were SnO2 nanosheets (NSs) assembled into a flower-like morphology with In2O3 particles grown in situ on the NSs. The In2O3-SnO2 sensor has excellent vapor sensitivity compared to pure SnO2. At an optimal temperature of 260 ℃, the In2O3-SnO2 sensor achieves a response value of 19.4 for acetone vapors at a concentration of 100 ppm. The composites still exhibit excellent gas-sensitized performance at low concentration (100 ppb). The improved gas-sensitized performance of In2O3-SnO2 composites is attributed to the sea urchin-like nanoflower morphology enriched with oxygen vacancies and the formation of n-n heterojunctions. To further substantiate its enhancing mechanism, the adsorption behavior of acetone molecules on the fabricated composite material was investigated through the utilization of density functional theory (DFT). This study confirms the enhanced gas sensing performance of In2O3-SnO2 heterojunction composites towards acetone and elucidates the enhancement mechanism by DFT calculations.