In situ investigation of water on MXene interfaces
Wahid Zaman, Ray A. Matsumoto, Matthew W. Thompson, Yu‐Hsuan Liu, Yousuf Bootwala, Marm Dixit, Slavomír Nemšák, Ethan J. Crumlin, Marta C. Hatzell, Peter T. Cummings, Kelsey B. Hatzell
Abstract
Significance Water organization at solid–liquid interfaces plays a critical role in a range of applications related to adsorption, membrane separations, energy storage, and catalysis. Currently, our understanding of molecular water at solid interfaces is limited to macroscopic and bulk measurement approaches. These interrogation techniques lack the spatial and temporal resolutions necessary to detect how water interacts with local heterogeneous chemical microenvironments governed by surface chemistry, solutes, etc. This work reveals the interaction between water and two-dimensional MXenes by combining in situ ambient-pressure X-ray photoelectron spectroscopy (XPS) and molecular dynamics simulation. This work demonstrates how the size of a solute (cation) governs transport within confined nanochannels and the hydration energy of the solute governs water adsorption/desorption properties at exposed surfaces.