Interlayer Structure

AM: Water-mediated exfoliation achieves kilogram-scale MXene, DFT/MD analysis of Li⁺–H₂O hydrogen bond network

The challenge of large-scale MXene preparation lies in achieving both high yield and preserving large flake size and low defects. Traditional methods such as sonication, oscillation, or strong shearing can improve exfoliation efficiency, but they easily break up the layer fragments and introduce defects, thus affecting electrical conductivity, mechanical properties, and ion sieving. This paper in *Advanced Materials* by the teams of He Daping and Shen Jie from Wuhan University of Technology and Tan Rui from Swansea University proposes water-mediated exfoliation as an alternative to strong mechanical exfoliation. The article modulates the coordination environment of Li⁺ in the interlayer by water molecules, forming a Li⁺–H₂O hydrogen bond network, weakening interlayer electrostatic attraction and van der Waals interactions, thus achieving kilogram-scale, monolayer, large-size, low-defect MXene preparation. The theoretical calculations, combining DFT and MD, explain why water molecules promote interlayer expansion and why defect-free MXene channels exhibit higher Li⁺/Mg²⁺ selectivity.