Al-doped GeS nanosheet as a promising sensing material for O-contained volatile organic compounds detection

[Display omitted] •Absorption properties of seven VOC molecules on GeS-based nanosheet were studied.•Enhanced interactions of O-contained VOCs were observed in Al-doped GeS.•Charge transfer and orbital hybridization are main enhanced mechanisms.•Magnetic properties could be utilized to further improve the selectivity. The adsorption characters of seven volatile organic compounds (VOCs) absorbed on intrinsic and Al-doped two-dimensional GeS were investigated by performing density functional theory. VOC molecules are physisorbed on pure GeS nanosheet by Van der Waals forces, however, the weak physical interactions could be significantly enhanced by Al doping. Strong interactions lead to multiplied adsorption energy and charge transfer, as well as improved sensitivity and thermodynamic stability. Orbital hybridization and charge redistribution between VOC molecules and Al-doped GeS substrate are dominant mechanisms of the enhanced interactions. In addition, influence of different functional groups to the magnetic properties of Al-doped GeS nanosheet was clarified, which paves the way to further promote the selectivity of sensors. Our calculating results might provide effective evidences to the design and fabrication of GeS-based VOC sensors with high sensitivity and selectivity at room temperature.