A density functional theory research on the interaction of H2X molecules with the Al2C nanosheet (X = O, S, Se, Te)

Abstract

The potential application of the 2D material Al2C, as catalysts and as sensor of the hazardous molecules H2S, H2Se and H2Te, is studied using theoretical methods. Density functional theory (DFT) has been applied to study the interaction between the pristine Al2C nanosheet and small molecules, such as H2O, H2S, H2Se and H2Te. Results show the Al2C nanosheet is a promising material to dissociate the studied molecules as well as its potential use as sensor of these molecules in molecular or dissociated state. Molecular interactions are weak even considering the London dispersion forces. Partial dissociative adsorption is strongly preferred to molecular adsorption for all four molecules. Applying the climbing image NEB method, the activation energy for H2O dissociation to OH-H is calculated in ≈ 0.1 eV whereas it is just a few meV for H2S, H2Se and H2Te partial dissociation. The calculated energy gap for the clean Al2C nanosheet is 1.078 eV whereas it is increased to 1.371, 1.338, 1.379 and 1.416 eV for molecular adsorption and to 1.209, 1.363, 1.370 and 1.388 eV for partial dissociative adsorption.

Keywords

• Al2C nanosheet
• Hazardous small molecules
• Water molecule
• Adsorption
• Dissociation
• Sensor