Proton conduction enabled highly selective acetonitrile detection at moderate operating temperature by using Ag-decorated sodium titanate nanoribbons

Abstract

The detection of acetonitrile is of great importance in a variety of fields related to environmental monitoring and public health. Poor selectivity and high operating temperature are two bottlenecks for existing acetonitrile sensors. In this study, high-performance acetonitrile detection was realized by using Ag-decorated sodium titanate nanoribbons (Ag-NTO NRs) which exhibited a unique surface proton-conductive sensing mechanism. Due to the high polarity of acetonitrile, acetonitrile promoted the proton conduction of Ag-NTO NRs, whereas other common reducing VOCs such as methanol, ethanol, and formaldehyde induced an opposite resistance change, resulting in an inherently high acetonitrile selectivity of Ag-NTO NRs. 5 % Ag-NTO NRs were capable of rapidly detecting acetonitrile (∼5 s) with extremely high selectivity and stability at 75 °C, while also exhibiting a low detection limit of 0.1 ppm (500 times lower than the IDLH value of acetonitrile). Finally, the proton-conductive sensing mechanism of Ag-NTO NRs was investigated in depth, and the influences from Ag loading, applied voltage, humidity, and operating temperature were discussed.