Computational investigation of formaldehyde adsorption on nitrogen-doped-γ-graphyne: modulation by an external electric field and mechanical strain.

Gas sensor devices are gaining widespread attention due to their vast potential for environmental and pollution monitoring applications. The current work investigates the sensing potential of the N-doped-γ-graphyne monolayer towards the formaldehyde (H2CO) molecule using density functional theory (DFT) with van der Waals (vdW) corrections. H2CO was found to be physisorbed on the N-doped-γ-graphyne monolayer with minimal binding energy, high binding distance, and low charge transfer. To improve the adsorption potential of the H2CO molecule on N-doped-γ-graphyne, we investigated the impact of an external electric field and mechanical compressive strain. Our findings show a gradual shift in the H2CO adsorption potential when applying such external perturbations. Such tunability makes it possible to achieve controlled trapping or reversible release of the H2CO molecule, which is highly desirable.