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High‐Resolution Electrochemical Mapping of the Hydrogen Evolution Reaction on Transition‐Metal Dichalcogenide Nanosheets
Author(s) -
Takahashi Yasufumi,
Kobayashi Yu,
Wang Ziqian,
Ito Yoshikazu,
Ota Masato,
Ida Hiroki,
Kumatani Akichika,
Miyazawa Keisuke,
Fujita Takeshi,
Shiku Hitoshi,
Korchev Yuri E.,
Miyata Yasumitsu,
Fukuma Takeshi,
Chen Mingwei,
Matsue Tomokazu
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201912863
Subject(s) - electrochemistry , transition metal , materials science , nanotechnology , chemistry , electrode , catalysis , organic chemistry
High‐resolution scanning electrochemical cell microscopy (SECCM) is used to image and quantitatively analyze the hydrogen evolution reaction (HER) catalytically active sites of 1H‐MoS 2 nanosheets, MoS 2 , and WS 2 heteronanosheets. Using a 20 nm radius nanopipette and hopping mode scanning, the resolution of SECCM was beyond the optical microscopy limit and visualized a small triangular MoS 2 nanosheet with a side length of ca. 130 nm. The electrochemical cell provides local cyclic voltammograms with a nanoscale spatial resolution for visualizing HER active sites as electrochemical images. The HER activity difference of edge, terrace, and heterojunction of MoS 2 and WS 2 were revealed. The SECCM imaging directly visualized the relationship of HER activity and number of MoS 2 nanosheet layers and unveiled the heterogeneous aging state of MoS 2 nanosheets. SECCM can be used for improving local HER activities by producing sulfur vacancies using electrochemical reaction at the selected region.