Theoretical insights of 2D carbon nitride (C3N) as a highly selective sensor for volatile analytes

In order to protect living organisms and environment, the detection of highly volatile pollutants has drawn significant attention in today’s globe. C3N, a 2D crystalline semiconductor material with exciting electronic and physiochemical characteristics is explored here as selective sensor against highly volatile toxic analytes. i.e., NCl3, COCl2, NF3, COS and CO. Theoretical insights of volatile pollutant@C3N complexes is obtained by following analyses: frontier molecular orbital (FMO), recovery time of sensor, natural bond orbital (NBO), interaction energy, electron density difference (EDD) and the quantum theory of atoms in molecules (QTAIM). The physisorption of volatile hazardous analytes on the surface of C3N is indicated by interaction energies that fall between − 7.28 kcal/mol and − 13.41 kcal/mol. 2D RDG plot along with 3D isosurfaces in NCI analysis verify the non-covalent interactions in studied analytes@C3N complexes. QTAIM analysis reveals that the studied contaminants becomes stable on C3N monolayer via electrostatic forces (COS, CO) and london dispersion or vdW forces (NCl3, COCl2 and NF3). Findings of NCI and QTAIM analyses have a good correlation with the results of interactional energy analysis. To comprehend the reusability of C3N monolayer, the recovery time of the complexes is computed. The electrical properties are also explained using FMO analysis where NCl3@C3N shows the highest reduction in energy gap on complexation, indicating that C3N surface is highly sensitive to the NCl3 analyte. According to the natural bond orbital (NBO) study, charge transfer value of NCl3@C3N is the highest, while that of COS@C3N is the lowest. These transfer of charge values have also been confirmed by EDD analysis. The main conclusions will motivate the researchers to develop a successful electrochemical sensor employing a C3N monolayer.