B3C2P3 monolayers based highly sensitive and selective room-temperature gas sensors for reusable NO and NO2 detection

Abstract

Motivated by the development of high-performance gas sensors using two-dimensional (2D) nanomaterials, herein using the combination methods of density functional theory (DFT) and nonequilibrium Green's function (NEGF), the structural, electronic, transport, and gas sensing properties of the B3C2P3 monolayer adsorbed with various gases (NO2, NO, NH3, SO2, H2S, CO2, CO, H2O, O2 and CH2O) have been systematically studied. The NO2 (or NO) molecules were chemically adsorbed (or strong physisorbed) on the B3C2P3 monolayer, while other molecules were weak-physically adsorbed on the substrate. Furthermore, only the NO2 and NO adsorption results in the remarkable change in electronic properties of B3C2P3. The transport properties such as current-voltage (I–V) characteristics and transmission functions indicate the B3C2P3 monolayer is highly sensitive and selective towards NO2 and NO gases. The recovery times of NO2 and NO were calculated to be 2.27 and 0.0785 ms at 300 K, indicating the reusability of the B3C2P3-based NO2 (NO) sensors. The existence of moisture hardly influences the adsorption of NO and NO2 on the B3C2P3 monolayer. Our results indicated that the B3C2P3 monolayer, as a room-temperature reusable gas sensor, is highly sensitive and selective for NO2 and NO detection regardless of the existence of moisture, O2 and CO2.