Critical role of water structure around interlayer ions for ion storage in layered double hydroxides

November 1, 2022

Title

Critical role of water structure around interlayer ions for ion storage in layered double hydroxides

Author

Tomohito Sudare, Takuro Yamaguchi, Mizuki Ueda, Hiromasa Shiiba, Hideki Tanaka, Mongkol Tipplook, Fumitaka Hayashi & Katsuya Teshima

Year

2022

Journal

Nature communications

Abstract

Water-containing layered materials have found various applications such as water purification and energy storage. The highly structured water molecules around ions under the confinement between the layers determine the ion storage ability. Yet, the relationship between the configuration of interlayer ions and water structure in high ion storage layered materials is elusive. Herein, using layered double hydroxides, we demonstrate that the water structure is sensitive to the filling density of ions in the interlayer space and governs the ion storage. For ion storage of dilute nitrate ions, a 24% decrease in the filling density increases the nitrate storage capacity by 300%. Quartz crystal microbalance with dissipation monitoring studies, combined with multimodal ex situ experiments and theoretical calculations, reveal that the decreasing filling density effectively facilitates the 2D hydrogen-bond networking structure in water around interlayer nitrate ions along with minimal change in the layered structure, leading to the high storage capacity.

Instrument

FT/IR-6100

Keywords

interlayer ions, layered materials,double hydroxides