Enhanced sensing performance of bimetallic Al/Ag-CNF network and porous PDMS-based triboelectric acetylene gas sensors in a high humidity atmosphere

We report a self-powered active gas sensor that can detect acetylene (C2H2) reliably and accurately by measuring the output voltages generated during contact electrification between bimetallic Al/Ag-carbon nanofiber (CNF) network and porous PDMS friction surfaces. Upon exposure to certain concentrations of C2H2, the triboelectric charging behavior of the sensor is altered due to a surface reaction between C2H2 molecules and the Al/Ag-CNF friction layer. The sensor exhibits excellent sensitivity of 83% and a quick response time of 88 s to C2H2 gas at a concentration of 1000 ppm. Importantly, the friction surfaces exhibit high hydrophobicity, which preferentially minimizes the influence of humidity and provides superior sensing performance even in a high humidity atmosphere (∼87% relative humidity). We believe that the proposed approach for harvesting energy and sensing can be advantageous in practical applications and will stimulate new research for the development of high performance, precise, reliable, and durable self-powered active gas sensors that can operate in hostile environments.