The local structure of sulfur vacancies on the basal plane of monolayer MoS2

Published

April 5, 2022

Author(s)

Angel Garcia-Esparza, Sangwook Park, Abrosham Hadi, John Vinson, Baxter Abraham, Alessandro Gallo, Dennis Nordlund, Taeho Roy Kim, Roberto Alonso-Mori, Jean-Luc Brédas, Xiaolin Zheng, Dimosthenis Sokaras

Abstract

The nature of the S-vacancy is central to controlling the electronic properties of monolayer MoS2. Understanding the geometric and electronic structures of the S-vacancy on the basal plane of monolayer MoS2 remains elusive. Here, operando S K-edge X-ray absorption spectroscopy shows the formation of clustered S-vacancies on the basal plane of monolayer MoS2 under reaction conditions (H2 atmosphere, 100-600 °C). First-principles calculations predict spectral fingerprints consistent with the experimental results. The Mo K-edge extended X-ray absorption fine structure shows the local structure as coordinatively unsaturated Mo with 4.1±0.4 S atoms as nearest neighbors (above 400 °C in H2 atmosphere). Conversely, the 6-fold Mo-Mo coordination in the crystal remains unchanged. Electrochemistry confirms similar active sites for hydrogen evolution. The identity of the S-vacancy defect on the basal plane of monolayer MoS2 is herein elucidated for applications in optoelectronics and catalysis.

Citation

ACS Nano

Volume

15

Issue

4

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acsnano.2c01388

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Citation

Garcia-Esparza, A. , Park, S. , Hadi, A. , Vinson, J. , Abraham, B. , Gallo, A. , Nordlund, D. , Kim, T. , Alonso-Mori, R. , Brédas, J. , Zheng, X. and Sokaras, D. (2022), The local structure of sulfur vacancies on the basal plane of monolayer MoS2, ACS Nano, [online], https://doi.org/10.1021/acsnano.2c01388, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933562 (Accessed October 9, 2025)