Comparative study on adsorption behaviour of the monolayer graphene, boron nitride and silicon carbide hetero-sheets towards carbon monoxide: Insights from first-principle studies

[Display omitted] •Adsorption behaviour of pristine GRA, BN, SiC and their in-plane heterostructures towards CO.•Angle strain at the junction of hetero-sheets made them slightly more unstable than the pristine sheets.•Variation in the CO orientation was observed for different sheets leading to the CO stretching frequency shift.•The interactions (physisorption) were dominated by weak Van der Waals forces.•GRA/SiC hetero-sheets showed better sensing behaviour towards CO. A comprehensive study on the sensitivity of graphene, boron nitride, silicon carbide and their in-plane hetero-sheets towards carbon monoxide (CO) was performed using first-principle density functional theory calculations. To rationalize the CO adsorption on pristine and hetero-sheets, molecular electrostatic potential contours, HOMO-LUMO distributions, the density of states plots, atomic charge distributions and quantum chemical descriptors were calculated. The optimized geometries showed that the CO molecule oriented itself at different angles with respect to sheets. A shift in the characteristic vibrational frequency of CO was observed through theoretically computed infra-red spectra. The maximum shift was observed for the GRA/SiC hetero-sheet. Charge analysis showed the partial charge transfer from the CO molecule to the adsorbent sheets. This was further confirmed by the HOMO-LUMO distributions of the interacting species. The reactivity descriptors calculated based on the HOMO-LUMO energies, molecular electrostatic potential contours and DOS plots showed that GRA/SiC hetero-structure exhibited better sensitivity towards CO than other sheets. The calculated adsorption energies, corrected for basis set superposition error, ranged from −3 to −10 kJ mol−1, confirming the physical nature of adsorption.