A molecular modeling study of pristine and Li-doped B₁₆N₁₆ nanocages for sensing G-series nerve agents using DFT-D3

The detection and removal of toxic warfare agents, such as G-series nerve agents, is a critical area of research for environmental safety and public health. This research uses density functional theory (DFT) to address the gap in understanding the molecular-level interactions of G-series nerve agents with boron nitride nanocages (BNNC) and lithium-doped boron nitride nanocages (Li-BNNC). The investigated nanostructures exhibited high negative adsorption energies, allowing the G-series nerve agents to adsorb strongly onto the BNNC and Li-BNNC surfaces. The Li-BNNC complexes undergo the chemisorption process with the adsorption energy, ranging from -31.819 kcal/mol to -33.635 kcal/mol. The findings of frontier molecular orbitals (FMOs) and density of states (DOS) indicated that the electronic characteristics of GS@BNNC and GS@Li-BNNC had been significantly changed, resulting in a smaller energy gap and higher conductivity. The Li-doping results in much lower energy gaps in Li-BNNC systems, such as 2.707 eV for Tabun@Li-BNNC, that cause higher electrical conductivity. Tabun@Li-BNNC has the highest electrical conductivity of 4.60 × 10¹² among Li-doped systems, and Tabun@BNNC has a high conductivity of 2.84 × 10¹² among undoped BNNC systems. Li-BNNC systems have higher electrical conductivity, which makes them good sensors for detecting G-series nerve agents. These findings provide a molecular-level understanding of the effect of Li-doping on BNNC-based nanomaterials and their potential for advancing nanotechnology-driven gas sensors.