Black phosphorene with Au modification: Oxynitride remover and hydrogen sensor

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, H 2, H 2 S, NO, NO 2, and SO 2 ) 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 NO x gases, and, surprisingly, the Au-doped black phosphorene exhibits sensitive physisorption towards H 2 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 NO x 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 H 2 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 NO x remover and H 2 sensor.