Au-catalyzed Fe2O3@SnO2 heterostructured nanowires for improved low-concentration acetone sensing

초록

This study presents the synthesis of Au and Fe2O3 nanoparticles (NPs) embedded on SnO2 nanowires (NWs) using a vapor-liquid-solid (VLS) and hydrothermal method. The resulting Au@Fe2O3@SnO2 NW composites demonstrated a remarkable response of 133.05 at an optimal operating temperature of 225 degrees C when exposed to 20 ppm of acetone gas, significantly outperforming pure SnO2 NWs by a factor of 23. These composites also exhibited excellent selectivity and long-term stability in acetone gas detection. A thorough investigation into the sensor's operational mechanism revealed that the interactions between acetone molecules and adsorbed oxygen, along with electron transfer processes, result in changes in sensor resistance. The superior gas-sensing properties are primarily attributed to the well-defined one-dimensional (1D) microstructure, featuring closely connected n-n heterojunctions of SnO2 and Fe2O3, which provide a large specific surface area with numerous active sites. These sites facilitate the reaction between acetone molecules and oxygen ions on the surface, enhanced by the catalytic effect of Au. This work underscores the potential of this fabrication method for developing gas sensors capable of detecting acetone at low ppm levels in a 225 degrees C environment.

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