Density Functional Theory Study of Ionic Liquid Adsorption on Circumcoronene Shaped Graphene

Abstract

Carbon materials have a range of properties such as high electrical conductivity, high specific surface area, and mechanical flexibility are relevant for electrochemical applications. Carbon materials are utilised in energy conversion-and-storage devices along with electrolytes of complementary properties. In this work, we study the interaction of highly concentrated electrolytes (ionic liquids) at a model carbon surface (circumcoronene) using density functional theory methods. Our results indicate the decisive role of the dispersion interactions that noticeably strengthen the circumcoronene-ion interaction. Also, we focus on the adsorption of halide anions as the electrolytes containing these ions are promising for practical use in supercapacitors and solar cells.

Adsorption of [BF4]− anion‐based ionic liquids on phosphorene, arsenene, and antimonene: A density functional theory study

“…The distances between fluoride atoms in [EMIM][BF 4 ], [MPI][BF 4 ], and [TMA][BF 4 ] and the BP, As, and Sb surfaces are 3.148 Å (2.794 and 3.160 Å), 3.043 Å (3.035 and 3.059 Å), and 3.143 Å (3.091 and 3.351 Å), respectively. The above‐mentioned distances between the ion moiety and the sheet are much greater than the sum of the covalent radiis while are close to the sum of the van der Waals radiis of the corresponding atoms with the shortest distances, which is in good agreement with the most stable adsorption configuration mentioned in previous studies [28, 32, 33, 41–49]. We can preliminarily conclude that the interaction between ILs and the 2D surfaces is mainly governed by non‐covalent forces.…”

“…For [MPI][BF 4 ] and [TMA][BF 4 ] system, we also observed the large changes of the hydrogen bond distances after adsorption. The significant changes in the configuration and hydrogen bond of ILs upon adsorption is similar to the previous researches of imidazolium‐ and pyridinium‐based ILs on the h‐BN or graphene surface [33, 46–48], but different from the report of [CH][BE]/graphene [28].…”

“…Since ILs can exist in closely contacted ion pairs, we studied the adsorption behavior of the three ion pairs on the surfaces of BP, As, and Sb nanosheets. In line with previous work [28, 32, 33, 41–49], we considered various configurations of ILs adsorbed on the nanosheets, as shown in Figure S1, and the related adsorption energies are shown in Table S3. The most stable structure of IL/2D adsorption system with the key interaction distances is displayed in Figure 1, and the adsorption energies are presented in Table 1.…”

“…Although some theoretical investigations have reported adsorption behavior of ILs on graphene, h‐BN, silicene, and bismuth surfaces, and so forth [28–33, 36, 37, 41–49], additional systematic study is required for ILs adsorbed on P, As, or Sb. Theoretical calculation of the interactions between ILs and P, As, and Sb nanosheets is essential for selection and evaluation of ILs and surfaces.…”

Calculation of core‐level electron spectra of ionic liquids

“…Therefore, the use of the ε(1s) method is justified for large systems, for example, complex interface models calculated with DFT (with or without periodic boundary conditions) or simulated with DFT‐based molecular dynamics, discussed in refs. [72‐76]. The ε(1s) method might also be useful when the changes in the XPS spectra upon variation of the chemical composition are a focus of study, for example, in studies of interfacial reactions.…”