A first-principles study of gas adsorption on germanene

Abstract

The adsorption of common gas molecules (N ₂, CO, CO ₂, H ₂O, NH ₃, NO, NO ₂, and O ₂) on germanene is studied with density functional theory.

Abstract

The adsorption of common gas molecules (N ₂, CO, CO ₂, H ₂O, NH ₃, NO, NO ₂, and O ₂) on germanene is studied with density functional theory. The results show that N ₂, CO, CO ₂, and H ₂O are physisorbed on germanene via van der Waals interactions, while NH ₃, NO, NO ₂, and O ₂ are chemisorbed on germanene via strong covalent (Ge–N or Ge–O) bonds. The chemisorption of gas molecules on germanene opens a band gap at the Dirac point of germanene. NO ₂ chemisorption on germanene shows strong hole doping in germanene. O ₂ is easily dissociated on germanene at room temperature. Different adsorption behaviors of common gas molecules on germanene provide a feasible way to exploit chemically modified germanene.