2D materials for ion adsorption and separation

Two-dimensional (2D) materials have attracted considerable attention due to their high surface area and unique layered structures, making them promising candidates for ion adsorption and separation applications. However, scalable production of high-quality 2D materials with tunable properties remains challenging. In this work, we developed an efficient method for preparing 2D materials via electrochemical lithium-ion intercalation and exfoliation. To further tailor their structural and chemical properties, the exfoliated materials were modified through phase engineering and covalent functionalization based on sulfur defects and C–S bonds, which enables precise sub-angstrom interlayer spacing control.

The modified 2D materials were systematically evaluated for water treatment and resource recovery applications, including heavy metal ion removal, seawater desalination, and precious metal recovery. Results show that covalent modification significantly enhances ion selectivity and improves the water stability of the materials. In particular, the precise sub-angstrom control of interlayer spacing allows highly efficient saltwater separation. The materials exhibited rapid adsorption kinetics, high adsorption capacities, and excellent recyclability, demonstrating their practical potential in real water matrices.

This study presents a versatile approach for the scalable preparation and precise functionalization of 2D materials and provides fundamental insights into the structure–property relationships governing ion adsorption, separation, and saltwater desalination. The findings highlight the promise of engineered 2D materials for environmental remediation and resource recovery, offering strategies to optimize both performance and stability for practical applications.

Dr. Liang Mei received his Ph.D. from City University of Hong Kong in 2023, where he also conducted postdoctoral research. His work focuses on the controllable synthesis of two-dimensional materials, adsorption-separation processes, and membrane-based water purification. He has published as first or corresponding author in journals such as Nature Reviews Chemistry, Nature Synthesis, Nature Protocols, and Nature Communications, and was awarded the Hong Kong RGC Junior Research Fellowship (JRFS