Vibrational signature of hydrated protons confined in MXene interlayers

作者：Mailis Lounasvuori, Yangyunli Sun, Tyler S. Mathis, Ljiljana Puškar, U. Schade, De‐en Jiang, Yury Gogotsi, Tristan Petit · 发表于：Nature Communications · 年份：2023 · DOI：10.1038/s41467-023-36842-0 · 被引用次数：85 · 研究领域：MXene and MAX Phase Materials、Advanced Memory and Neural Computing、2D Materials and Applications

Abstract The hydration structure of protons has been studied for decades in bulk water and protonated clusters due to its importance but has remained elusive in planar confined environments. Two-dimensional (2D) transition metal carbides known as MXenes show extreme capacitance in protic electrolytes, which has attracted attention in the energy storage field. We report here that discrete vibrational modes related to protons intercalated in the 2D slits between Ti 3 C 2 T x MXene layers can be detected using operando infrared spectroscopy. The origin of these modes, not observed for protons in bulk water, is attributed to protons with reduced coordination number in confinement based on Density Functional Theory calculations. This study therefore demonstrates a useful tool for the characterization of chemical species under 2D confinement.