Electrochemical sensing potential of novel C2N2 bilayer surface for the detection of toxic analytes

Abstract

A novel 2D carbon nitride (C₂N₂) bilayer surface owing two atomic layers in a unit cell with semiconducting nature is a new attraction in the adsorption of toxic pollutants and environmental remediation. In this regard, 2D crystalline (C₂N₂) bilayer surfaces are potential candidates for the adsorption of chemical warfare agents (phosgene, phosgene oxime and diphosgene) and volatile organic compounds (carbon disulfide, carbon oxysulfide). The complexation behavior of studied analytes on the C₂N₂ surface has been systematically investigated using non-covalent interactions (NCI), interaction energy, quantum theory of atoms in molecules (QTAIM), electron density difference (EDD), natural bond orbital (NBO) and frontier molecular orbital (FMO) analyses. Interaction energies lying between −6.94 kcal mol⁻¹ to −19.51 kcal mol⁻¹ indicate the physisorption concerning toxic analytes on the C₂N₂ bilayer surface. NCI and QTAIM analyses reveal that the studied pollutants are stabilized over C₂N₂ surface via weak van der Waals and electrostatic interactions. NCI and QTAIM analyses results are nicely correlated with the interaction energy analysis. Natural bond orbital (NBO) analysis indicates that PhO@C₂N₂ has the maximum value for transfer of charge, whereas COCl₂@C₂N₂ has the least charge transfer value. EDD analysis has further verified these transfer of charge values. The electronic properties are also elaborated based on frontier molecular orbital analysis. The lowest energy gap upon complexation is calculated for COCl₂@C₂N₂ complex with an energy gap (H-L) of 4.10 eV. Overall, the key findings might be productive for the scientific community to create an efficient electrochemical sensor using C₂N₂ bilayer.