Document Type

Article

Publication Date

3-1-2022

Publication Title

Journal of Molecular Liquids

Volume

349

Keywords

Deep eutectic solvents, DFT, Hexagonal boron-nitride, Noncovalent interaction, Structural defects

Abstract

Hexagonal boron nitride is a promising material for a variety of electronic, optical, and material science applications. Both the synthesis of the material through exfoliation, and its various applications almost inevitably require its solvation. Deep eutectic solvents (DES) are extremely useful solvents for these types of applications due to their non-volatility, inflammability, biocompatibility, and reasonable cost. There are many different deep eutectic solvents available, and their suitability for any given application is particularly dependent on the specific of their structure. DES have been examined computationally for use with boron nitride, but these calculations use idealized, perfect boron nitride sheets instead of the more realistic, defect-containing systems. In this report, we investigated four DESs with two experimentally observed defective boron nitride, one with a single boron vacancy, the other with a single nitrogen vacancy. All DESs bound with higher affinity to the defective boron nitride than to the pristine surface. Charge transfer was minimal in all cases although the surfaces tended to donate electron density to the solvents. The interactions between the solvents and the surfaces are primarily non-covalent although in several cases natural bond order analysis indicates a partial covalent interaction that helps explain the higher-than-expected affinity for particular DES. The DESs have little effect on the predicted optical behaviour of the pristine boron nitride but do significantly change the adsorption spectrum of the defective boron nitride nanoflakes; the effect on bulk material might be limited. Together these results suggest that the choice of DES can either be made to limit any effect on the properties of the material (urea-choline chloride) or to affect the optical and electronic nature of the material (benzoic acid-choline chloride).

DOI

10.1016/j.molliq.2021.118122

ISSN

01677322

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