Cyclic Voltammetry and X-ray Absorption Spectroscopy of Nickel Oxide in the Ionic Liquid 1-Ethyl-3-Methyl Imidazolium Chloride/Aluminum Chloride

Abstract

Transition metal chlorides have been examined in situ in ionic liquids (ILs) using cyclic voltammetry (CV) but the oxides of these metals have not received as much attention. In this study, the structure of nickel oxide in the ionic liquid, 1-ethyl-3-methyl imidazolium chloride (EMIC) and aluminum chloride has been investigated. The NiO in EMIC/AlCl3 IL was examined with CVs and Extended X-ray Absorption Fine Structure (EXAFS) in both Lewis acidic and basic IL solutions. The CV of NiO in both acidic and basic EMIC/AlCl3 ILs shows similarities with the CV of NiCl2 in these ILs. The EXAFS data for the NiO and anhydrous NiCl2 in these acidic and basic IL solutions are also analogous, indicating that some corresponding molecular structures may have formed and these are discussed in detail.

Anion De/Intercalation in Nickel Hydroxychloride Microspheres: A Mechanistic Study of Structural Impact on Energy Storage Performance of Multianion-Containing Layered Materials

“…Fourier-transformed EXAFS curve of Ni­(OH) 2 is characterized by two main peaks at 1.93 and 3.04 Å (Figure b), corresponding to the Ni–O and neighboring Ni–Ni coordinations, respectively . In comparison with Ni­(OH) 2 , an obvious peak at 2.30 Å for the as-prepared sample emerged, corresponding to Ni–Cl coordination based on the assignment in literature. , In addition, both Ni–O bond length (1.84 Å) and Ni–Ni bond length (3.19 Å) of the as-prepared sample showed deviations. All these results can be explained by the introduction of Cl – into the lattice.…”

“…h i b i t e d .in literature 43,44. In addition, both Ni−O bond length(1.84 Å) and Ni−Ni bond length (3.19 Å) of the as-prepared sample showed deviations.…”