Publication

Abstract : There is a huge demand for highly selective and sensitive chemi-resistive gas-sensors for different applications in the IoT-based modern era. Since the metal oxides chemi-resistive sensors suffer from the higher operating temperatures and drifts in the sensing response, rigorous efforts are in line to find more suitable sensing material with a significant figure of merits. Towards this, we report metal-free 2D mesoporous g-C3N4 nanosheets for the highly selective and sensitive detection of ethanol at ambient temperature (303 K). The synthesized mesoporous g-C3N4 nanosheets showed a high surface area of 172 m2g−1, which is 10.5 times higher than that of bulk g-CN (g-C3N4) reported in the literature. The synthesized mesoporous g-C3N4 nanosheets showed a maximum sensing response of S= 182.4 @ 46%RH towards 50 ppm of ethanol vapor with the lowest detection limit of 0.5 ppm (500 ppb) at room temperature. The response and recovery times of the mesoporous g-C3N4 sensor were 34/30 s and 115/121 s, respectively towards 0.5 ppm and 50 ppm of ethanol at room temperature. The sensor showed reproducible results with 4.89% and 7.33% drifts in the observed sensing response towards 0.5 and 50 ppm of ethanol, respectively over the time indicated good stability. This is the first time we report the room temperature ethanol sensing characteristics of metal-free mesoporous g-C3N4 with appreciable response characteristics. The room temperature sensing with such a figure of merits opens a new venue for the heterogeneous metal-free polymeric materials for sensing in an ambient atmosphere with its rich chemical diversity.