Narrow Results

Atomic adsorptions of N, C and O on silicene and molecular adsorptions of N₂ and CO on silicene have been investigated using the density functional theory (DFT) calculations. For the atomic adsorptions, we find that the N atom has the most stable adsorption with a higher adsorption energy of 8.207 eV. For the molecular adsorptions, we find that the N₂ molecule undergoes physisorption while the CO molecule undergoes chemisorption, the corresponding adsorption energies for N₂ and CO are 0.085 and 0.255 eV, respectively. Therefore, silicene exhibits more reactivity towards the CO adsorption than the N₂ adsorption. The differences of charge density and the integrated charge calculations suggest that the charge transfer for CO adsorption ($\sim$0.015$e$) is larger than that for N₂ adsorption ($\sim$0.005$e$). This again supports that CO molecule is more active than N₂ molecule when they are adsorbed onto silicene.