The efficient capture of carbon dioxide (CO₂) using polymer, supported ionic liquids (ILs) remains challenging due to limited understanding of atomic-scale interaction mechanisms. Here, a polystyrene (PS) oligomer supported by an amidinium chloride-based IL is proposed as a CO₂-absorbing material. Density functional theory (DFT) calculations were employed to investigate the structural, electronic, and intermolecular interaction energy characteristics of the PS oligomer, amidinium chloride ILs, CO₂, and their binary and ternary complexes. Molecular electrostatic potential maps (MEPs), reduced density gradient (RDG) plots with non-covalent interaction (NCI) snapshots, quantum theory of atoms in molecules critical point (CP) analysis, and electron localization function (ELF) analysis reveal pronounced hydrogen bonding and dispersion interactions between PS and IL that modulate the electronic environment of the IL anion, which is the primary CO₂ binding site. Interaction energy calculations show that the ternary PS–IL–CO₂ complex exhibits a significantly enhanced binding energy compared to the isolated IL–CO₂ complex, providing quantitative evidence for the cooperative role of the PS support. The results indicate enhanced CO₂ binding in the presence of PS supported by ILs, driven by cooperative electrostatic and dispersion interactions. These findings provide molecular-level insights into CO₂ capture mechanisms in polymer–IL hybrid systems.

Understanding the atomic-level behavior of photocatalysts under hydrated conditions is essential for improving hydrogen production efficiency. In this work, density functional theory calculations and classical all-atom molecular dynamics simulations were performed to investigate the intra- and intermolecular interactions of rod- and cluster-shaped cadmium sulfide in the presence of implicit and explicit water, respectively. The density functional theory optimized geometries, reduced density gradient, noncovalent interaction, critical point, and molecular electrostatic potential maps were examined using the LC-ωPBE functional with the LANL2DZ basis set and the IEFPCM implicit solvation model, while explicit hydration was modeled via classical all-atom molecular dynamics simulations by obtaining molecular snapshots and radial distribution functions. Density functional theory results revealed that rod-shaped cadmium sulfide exhibits stronger directional bonding and higher electronic localization compared to cluster-shaped cadmium sulfide, while classical all-atom molecular dynamics simulations showed that water molecules preferentially interact with surface S atoms of cadmium sulfide sites. This atomistic insight clarifies how morphology and hydration jointly modulate cadmium sulfide electronic structure and reactivity, providing guidance for the rational design of efficient cadmium sulfide-based photocatalysts for solar-driven water splitting.

This study employs Density Functional Theory (DFT) calculations and traditional all-atom Molecular Dynamics (MD) simulations to reveal atomistic insights into a task-specific Deep Eutectic Solvent (DES) supported by graphene oxide with the aim of mimicking its application in the natural gas desulfurization process. The DES, composed of N,N,N′,N′-tetramthyl-1,6-hexane diamine acetate (TMHDAAc) and methyldiethanolamine (MDEA) supported by graphene oxide, demonstrates improved efficiency in removing hydrogen sulfide from methane. Optimized structure and HOMO-LUMO orbital analyses reveal the distinct spatial arrangements and interactions between hydrogen sulfide, methane, and DES components, highlighting the efficacy of the DES in facilitating the separation of hydrogen sulfide from methane through DFT calculations. The radial distribution function (RDF) and interaction energies, as determined by traditional all-atom MD simulations, provide insights into the specificity and strength of the interactions between the DES components supported by graphene oxide and hydrogen sulfide. Importantly, the stability of the DES structure supported by graphene oxide is maintained after mixing with the fuel, ensuring its robustness and suitability for prolonged desulfurization processes, as evidenced by traditional all-atom MD simulation results. These findings offer crucial insights into the molecular-level mechanisms underlying the desulfurization of natural gas, guiding the design and optimization of task-specific DESs supported by graphene oxide for sustainable and efficient natural gas purification.