Solid-State NMR Study of Hydrated Intercalation Compounds of Molybdenum Disulfide

Abstract

Solid-state NMR has been used to study the local coordination environments of the protons and alkali metal cations in hydrated alkali metal intercalation compounds of MoS 2 , A x (H 2 O) y -MoS 2 (A ) Li, Na, K, Cs). The dynamic behavior of the water molecules, which are coordinated to the intercalated A + cations, is consistent with an ordered quasi two-dimensional translational motion at room temperature. In Li x (H 2 O) y MoS 2 , the hydrated Li + cations occupy two distinct sites in the van der Waals gap that are connected by dynamic processes. Partially random motions of the H 2 O molecules are activated at room temperature.

Metallic 1T phase MoS2 nanosheets as supercapacitor electrode materials

“…These expansion values are higher than the hydrated cation sizes of Li + (H 2 O) 2 , Na + (H 2 O) 2 and K + (H 2 O). The observed expansion values are consistent with previous XRD and NMR studies of MoS 2 intercalation compounds 22,28,29 . Interestingly, unlike neutral electrolytes, the (001) peak is absent after charging in H 2 SO 4 .…”

Active peroxo titanium complexes: syntheses, characterization and their potential in the photooxidation of 2-propanol

“…The 7 Li MAS-NMR spectrum of 1 shows a signal at 1.1 ppm that is consistent with the hydrated lithium cations described in the literature. 9 The determined structure of this compound is in harmony with the corresponding Raman spectrum. Sharp bands at 894 cm À1 for n O-O and 636 cm À1 for n Ti-O 2 are assigned to non-bridging Z 2 -peroxo ligands.…”

Electron Diffraction Study of Intercalation Compounds Derived from 1T-MoS2

“…Obviously, the mobility of the water molecules is unusually high and leads to rotations around the cations and to translational movements within the van der Waals gaps (20,21).…”