Document Type

Article

Publication Date

4-1-2021

Publication Title

Journal of Molecular Liquids

Volume

327

Keywords

Deep eutectic solvent, Defective graphene, DFT, Graphene nanoflake, Noncovalent interaction

Abstract

The interaction of four deep choline chloride-derived eutectic solvents (DESs) with both graphene nanoflakes (GNF) and its defective double-vacancy and Stone–Wales forms (DV-GNF and SW-GNF), was evaluated using density functional theory (DFT). The presence of defects increases the adsorption energy of DESs, following the order DES∩DV-GNF > DES∩SW-GNF > DES∩GNF. Non-covalent interaction and energy decomposition analyses show that the interactions are noncovalent and dominated by dispersive forces. Furthermore, we find that the presence of aromatic moieties in the DESs increases the van der Waals interactions with the surfaces. These interactions decrease the HOMO-LUMO (Eg) energy gap of the surfaces and thus increase reactivity. Reactivity parameter calculations indicate that the chemical potential (μ) and chemical hardness (η) of the complexes follow the order DES∩GNF > DES∩SW-GNF > DES∩DV-GNF. This order is reversed for the global softness (S) and electrophilicity index (ω). Time-dependent DFT (TD-DFT) calculations predict that the adsorption of DESs onto DV-GNF and SW-GNF should red shift absorption, while the absorption spectrum of GNF surface remains unchanged upon DES adsorption. The biggest changes in the absorption spectra are observed upon adsorption of DESs on the DV-GNF surface due to the stronger affinity of the DESs for this surface.

DOI

10.1016/j.molliq.2020.114850

ISSN

01677322

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