Carbon nitride 2-D surface as a highly selective electrochemical sensor for V-series nerve agents

Abstract

Herein, carbon nitride 2-D surface (C2N) was studied as an electrochemical sensor for chemical warfare agents (CWA; A-230, A-232, A-234, and VR). The deep insight of analytes@C2N complexation was obtained by interaction energy, SAPT0, NCI, QTAIM, EED, and FMO analyses. The interaction energies results indicate that these CWAs are physisorbed onto the surface where BSSE corrected interaction energies range from −14.42 kcal/mol to −15.99 kcal/mol. Moreover, SAPT0 analysis revealed that dispersion interactions are the dominant component which amount to nearly 61% of overall SAPT0 interaction energies. SAPT0 analysis results are consistent with interaction energies. The nature of interactions was also quantified by NCI and QTAIMs analysis. NBO analysis showed that the highest amount of charge transfer is observed in A232@C2N (−0.018 e−), while the least amount of charge transfer is seen in VR@C2N. The EDD analysis also verified the results of NCI, QTAIM and NBO analyses. A short recovery time of 0.027 s at 298 K for desorption of VR from C2N surfaces was calculated. VR adsorption onto C2N surface caused the highest change in the HOMO-LUMO energy gap (2.68 eV) compared to bare C2N (3.71 eV), which reveals the potential of C2N as an electrochemical sensor for VR. The complexation of A-230, A-232, and A-234 had a negligible effect on the HOMO-LUMO energy gap. Among all complexes, HOMO-LUMO excitation is associated with charge transfer from analytes to the C2N surface.