Effective Adsorption of a-series Chemical Warfare Agents on Graphdiyne Nanoflake; A DFT Study

Abstract Chemical warfare agents (CWAs) are highly poisonous and their presence may cause diverse effect not only on living organisms but on environment as well. Therefore, their detection and removal in a short time span is very important. In this regard, here the utility of graphdiyne (GDY) nanoflake is studied theoretically as an electrochemical sensor material for the hazardous CWAs including A-230, A-232, A-234. Herein, we explain the phenomenon of adsorption of A-series CWAs on GDY nanoflake within the density functional theory (DFT) framework. The characterization of adsorption is based on optimized geometries, BSSE corrected energies, SAPT, RDG, FMO, CHELPG charge transfer, QTAIM and UV-Vis analyses. The calculated counterpoise adsorption energies for reported complexes range from -13.70 to -17.19 kcal mol-1. These adsorption energies show that analytes are physiosorbed onto GDY which usually takes place through noncovalent interactions. The noncovalent adsorption of CWAs on GDY is also attributed by the SAPT0, RDG and QTAIM analyses. These properties also reveal that dispersion factors dominate in the complexes among many noncovalent components (exchange, induction, electrostatic, steric repulsion). In order the estimate the sensitivity of GDY, the %sensitivity and average energy gap variations are quantitatively measured by energies of HOMO and LUMO orbitals. In term of adsorption affinity of GDY, UV-Vis analysis, CHELPG charge transfer and DOS analysis depict an appreciable response towards these toxic CWAs.