Mo Atom Rearrangement Drives Layer-Dependent Reactivity in Two-Dimensional MoS 2

作者：Zifan Wang, Jiaxuan Wen, Tina Mihm, Shaopeng Feng, Kelvin Huang, Jing Tang, Tianshu Li, Liangbo Liang, Sahar Sharifzadeh, Keji Lai, Xi Ling · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c12760 · 被引用次数：5 · 研究领域：2D Materials and Applications、MXene and MAX Phase Materials、Advanced Photocatalysis Techniques

Two-dimensional (2D) materials offer a valuable platform for manipulating and studying chemical reactions at the atomic level, owing to the ease of controlling their microscopic structure at the nanometer scale. While extensive research has been conducted on the structure-dependent chemical activity of 2D materials, the influence of structural transformation during the reaction has remained largely unexplored. In this work, we report the layer-dependent chemical reactivity of MoS 2 during a nitridation atomic substitution reaction and attribute it to the rearrangement of Mo atoms. Our results show that the chemical reactivity of MoS 2 decreases as the number of layers is reduced in the few-layer regime. In particular, monolayer MoS 2 exhibits significantly lower reactivity compared with its few-layer and multilayer counterparts. Atomic-resolution transmission electron microscopy (TEM) reveals that MoN nanonetworks form as reaction products from monolayer and bilayer MoS 2, with the continuity of the MoN crystals increasing with layer number, consistent with the local conductivity mapping data. The layer-dependent reactivity is attributed to the relative stability of the hypothetically formed MoN phase, which retains the number of Mo atomic layers present in the precursor. Specifically, the low chemical reactivity of monolayer MoS 2 is attributed to the high energy cost associated with Mo atom diffusion and migration necessary to form multilayer Mo lattices in the thermodynami...