Systematic study of the structure-property relationship of C24N24 nanoclusters for the detection and electrochemical sensing of chemical warfare agents: Molecular modelling at DFT level

Abstract

Chemical warfare agents (CWAs) are highly poisonous and dangerous to all forms of life. Their rapid discovery and removal are crucial for the protection of people and the environment. Current technology still falls short of the 100 % efficiency threshold. Therefore, we make use of the efficient three-dimensional C24N24-nanostructured material for the rapid detection and electrochemical sensing of CWAs phosgene (COCl2) and thiophosgene (CSCl2) by employing benchmark DFT and TD-DFT investigations. Nine stable configurations of C24N24 nanocluster were quantum chemically designed facing through chlorine, oxygen, sulphur atoms of phosgene and thiophosgene and with their planar orientations on the large and small cavities of the nanocluster. Optimization of geometry, FMO, adsorption energies, NBO, QTAIM, and NCI, were the methods for evaluating the interaction between chemical warfare agents and the nanocluster. Fine-tuning of electronic properties; recovery time (∼3 × 10−14s−1), electrical conductivity (∼1.84 × 109), sensitivity (∼0.050), electrophilicity index (1.76–1.68 eV), hardness (3.52–3.37 eV), softness (∼0.15 eV), energy gap (2.85–2.55 eV), and interaction distance (4.274±1.245A0), values ascertain the elevated reactivity and an imperishable sensitivity of the C24N24 nanocluster towards the investigated CWAs. The energy gap, QTAIM, NCI, sensitivity, and recovery time analysis confirmed that the Pl*@C24N24-SC nanostructured material developed as the most suited surface for the effective finding of phosgene and Pl@C24N24-LC for thiophosgene. Adsorption energies of −8.490 and -8.507 kcal/mol for the Pl*@C24N24-SC and Pl@C24N24-LC complexes, respectively, were the deciding factors. The C24N24 nanocluster has the highest sensitivity and shortest recovery time for S@C24N24-LC and Pl@C24N24-LC complex with the value of 0.0509 and 3.23 × 10−14s−1 which shows the potential of C24N24 nanocluster as a promising influential sensing material to monitor CWAs phosgene and thiophosgene. This theoretical framework will assist experimentalists in detecting toxic CWAs by using C24N24 nanocluster-based sensor.