C3N monolayers as promising candidates for NO2 sensors.

Searching for suitable materials for NO 2 sensing has important scientific significance and application value. First-principles calculations have been performed on the adsorption of NO 2 and its various interfering gases on the pristine C 3 N monolayer (p-C 3 N) and the B-doped C 3 N monolayer. The studies on the adsorption stability, geometric structure, charge transfer, and electronic structure indicate that the p-C 3 N is a promising room-temperature NO 2 sensor, with high selectivity and sensitivity, and good reversibility. For the B-doped C 3 N monolayer, the calculated formation energies suggest that B doping into the C 3 N lattice is thermodynamically highly favorable. Furthermore, B doping by replacing the N atom in the C 3 N monolayer should can further improve the sensing selectivity and sensitivity of the C 3 N monolayer toward NO 2 . However, it is noted that a large adsorption energy for NO 2 indicates that the B-doped C 3 N monolayer may be reversibly operated above the room temperature. The possible reason for the distinct adsorption behaviors of the various molecules is also provided. Our theoretical studies indicate the great potential of the C 3 N-based two-dimensional semiconductor as good NO 2 gas sensors. [ABSTRACT FROM AUTHOR]