MEMS Gas Sensors Based on In₂O₃-Decorated SnO₂ Nanosheets for Aniline Detection

Aniline monitoring holds significant importance across various industries. In this study, we propose a microelectromechanical systems (MEMS) gas sensor employing In2O3-decorated SnO2 nanosheets for aniline detection. Ultrathin nanomaterials were prepared via a facile hydrothermal procedure. The results indicate the gas sensor shows excellent sensitivity to aniline, whereas a response (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {a}}$ </tex-math></inline-formula>/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {g}}$ </tex-math></inline-formula>) of 7.3 to 70 ppm aniline was achieved (three times better than that of pristine SnO2) with a low power consumption of 21 mW. The improved sensing characteristics may be ascribed to the synergistic effects arising from the enlarged pore channels and active sites of nanosheets, as well as unique electron transformations and chemical sensitization occurring at the n-n heterojunctions, providing an efficient route for the fabrication of selective aniline gas sensors.