Black phosphorene with Au modification: Oxynitride remover and hydrogen sensor

Abstract

Effective detecting toxic gases and the clean energy hydrogen is urgently necessary in industrial production and our daily life. Here, the sensing properties of Au-adsorbed/doped black phosphorene monolayer towards six different gases (CO, H2, H2S, NO, NO2, and SO2) are theoretically investigated through density functional theory in combination with the non-equilibrium Green’s function approach. The calculated adsorption energy, the charge transfer, the electron localization function, the band structure, and the density of states reveal that the Au-adsorbed/doped black phosphorene exhibits sensitive chemisorption to NOx gases, and, surprisingly, the Au-doped black phosphorene exhibits sensitive physisorption towards H2 molecules. The calculated recovery time and current–voltage curves show that the Au-adsorbed/doped black phosphorene device acts as an ultra-sensitive (71%–100% sensitivity) remover of NOx molecules, and, importantly, the Au-doped black phosphorene sensor achieves a highly sensitive (85% sensitivity), selective, and reusable (0.01 ns recovery time) detection of H2 at room temperature. Our results provide a theoretical basis for the potential applications of the Au-adsorbed/doped black phosphorene in gas-sensing, especially in the desirable NOx remover and H2 sensor.