Oxidation kinetics and non-Marcusian charge transfer in dimensionally confined semiconductors

Ning Xu; Li Shi; Xudong Pei; Weiyang Zhang; Jian Chen; Zheng Han; Paolo Samorì; Jinlan Wang; Peng Wang; Yi Shi; Songlin Li

doi:10.1038/s41467-023-39781-y

Oxidation kinetics and non-Marcusian charge transfer in dimensionally confined semiconductors

Nat Commun. 2023 Jul 10;14(1):4074. doi: 10.1038/s41467-023-39781-y.

Authors

Ning Xu^#¹, Li Shi^#^{2

3}, Xudong Pei^#⁴, Weiyang Zhang⁴, Jian Chen¹, Zheng Han⁵, Paolo Samorì⁶, Jinlan Wang^{7

8}, Peng Wang⁹, Yi Shi¹⁰, Songlin Li¹¹

Affiliations

¹ School of Electronic Science and Engineering, National Laboratory of Solid-State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, China.
² Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, 211189, China.
³ State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
⁴ College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210023, China.
⁵ Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006, China.
⁶ University of Strasbourg, CNRS, ISIS UMR 7006, 8 allée Gaspard Monge, F-67000, Strasbourg, France.
⁷ Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, 211189, China. jlwang@seu.edu.cn.
⁸ Suzhou Laboratory, Suzhou, 215125, China. jlwang@seu.edu.cn.
⁹ Department of Physics, University of Warwick, CV4 7AL, Coventry, UK. peng.wang.3@warwick.ac.uk.
¹⁰ School of Electronic Science and Engineering, National Laboratory of Solid-State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, China. yshi@nju.edu.cn.
¹¹ School of Electronic Science and Engineering, National Laboratory of Solid-State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, China. sli@nju.edu.cn.

^# Contributed equally.

Abstract

Electrochemical reactions represent essential processes in fundamental chemistry that foster a wide range of applications. Although most electrochemical reactions in bulk substances can be well described by the classical Marcus-Gerischer charge transfer theory, the realistic reaction character and mechanism in dimensionally confined systems remain unknown. Here, we report the multiparametric survey on the kinetics of lateral photooxidation in structurally identical WS₂ and MoS₂ monolayers, where electrochemical oxidation occurs at the atomically thin monolayer edges. The oxidation rate is correlated quantitatively with various crystallographic and environmental parameters, including the density of reactive sites, humidity, temperature, and illumination fluence. In particular, we observe distinctive reaction barriers of 1.4 and 0.9 eV for the two structurally identical semiconductors and uncover an unusual non-Marcusian charge transfer mechanism in these dimensionally confined monolayers due to the limit in reactant supplies. A scenario of band bending is proposed to explain the discrepancy in reaction barriers. These results add important knowledge into the fundamental electrochemical reaction theory in low-dimensional systems.