Investigating the potential of carbon nitride as a new sensing material for NOx (N2O, N2O3, N2O4, and N2O5): a DFT study

Herein, DFT study was used to investigate the carbon nitride C6N8 as a potential detector of noxious gases, specifically nitrous oxide (N2O), dinitrogen tri-oxide (N2O3), dinitrogen tetra-oxide (N2O4), and dinitrogen penta-oxide. (N2O5). The Physiosorption process was notified after the adsorption of N2O (-12.6463 kJ mol(-1)), N2O3 (-40.1466 kJ mol(-1)), N2O4 (-23.8512 kJ mol(-1)), and N2O5 (-29.7947 kJ mol(-1)) on C6N8. The adsorption behavior shows weak interactions in the complexes which depicts the stability trend as N2O3@C6N8 > N2O5@C6N8 > N2O4@C6N8 > N2O@C6N8. Various analyses and techniques were employed to evaluate the sensing capability. Electronic parameters such as FMO, ELF, NBO, UV-visible spectrum, and DOS were performed to notify the detectable change in the sensing surface after the adsorption of the gases being studied. The existence of non-covalent interactions was confirmed by Symmetry Adopted Perturbation Theory (SAPT0), QTAIM, NCI, and IRI plots. Moreover, SAPT0 confirmed the greater contribution of E-dispersion in N2O@C6N8. ESP (MEPs) visualization confirmed the interactions, as the nitrogen atoms of the surface are electron dense regions for the analytes to attack. Chemical stability and selectivity were evidenced by the stability parameters and the formation of new states in the DOS spectrum, respectively. Significant recovery time performance was observed after evaluating the recovery of analyte@C6N8 complexes at an appropriate temperature. These results suggest C6N8 theoretically as a potentially active sensing surface and it will enhance the interest of the experimental researchers in fabricating a sensing device using this material for the determination of even minute concentrations of the toxic gases.