Abstract
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 MoS2during a nitridation atomic substitution reaction and attribute it to the rearrangement of Mo atoms. Our results show that the chemical reactivity of MoS2decreases as the number of layers is reduced in the few-layer regime. In particular, monolayer MoS2exhibits 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 MoS2, 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 MoS2is attributed to the high energy cost associated with Mo atom diffusion and migration necessary to form multilayer Mo lattices in the thermodynamically stable MoN phase. This study underscores the critical role of lattice rearrangement in governing chemical reactivity and highlights the potential of 2D materials as versatile platforms for advancing the understanding of materials chemistry at the atomic scale.
| Original language | English |
|---|---|
| Pages (from-to) | 35109-35117 |
| Number of pages | 9 |
| Journal | Journal of the American Chemical Society |
| Volume | 147 |
| Issue number | 38 |
| DOIs | |
| State | Published - Sep 24 2025 |
Funding
Research is primarily supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award DE-SC0021064. Work by X.L. was also supported by the National Science Foundation (NSF) under Grant Nos. 1945364 and 2111160. The microwave microscopy work (J.W., S.F., K.L.) was supported by the Welch Foundation (Grant No. F-1814). K.L. was also supported by NSF under Grant DMR-2426989. Computational studies by T.M., K.H., and S.S. were supported by DOE BES under Award number DE-SC0023402. L.L. acknowledges work at the Center for Nanophase Materials Sciences, which is a U.S. Department of Energy Office of Science User Facility. This work was performed in part at the Harvard University Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF award no. ECCS-2025158. We would like to acknowledge computational resources from the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, and Boston University’s Research Computing Services.