Electrochemical Detection of Isolated Nanoscale Defects in 2D Transition Metal Dichalcogenides

0559120 - ÚFCH JH 2023 RIV US eng J - Journal Article
Cabré, M. B. - Paiva, A. E. - Velický, Matěj - Colavita, P.E. - McKelvey, K.
Electrochemical Detection of Isolated Nanoscale Defects in 2D Transition Metal Dichalcogenides.
Journal of Physical Chemistry C. Roč. 126, č. 28 (2022), s. 11636-11641. ISSN 1932-7447. E-ISSN 1932-7455
Grant - others:AV ČR(CZ) LQ200402201
Program: Prémie Lumina quaeruntur
Institutional support: RVO:61388955
Keywords : electrochemistry * redox reactions * electrodes
OECD category: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Impact factor: 3.7, year: 2022
Method of publishing: Limited access

We show that nanometer and sub-nanometer scale defects in two-dimensional transition metal dichalcogenides can be detected electrochemically using scanning electrochemical cell microscopy (SECCM). We detect isolated anomalous electrochemical responses for the hexaammineruthenium ([Ru(NH3)6]3+/2+) redox couple on mono-, bi-, and trilayer regions of mechanically exfoliated MoS2. These anomalous sample points display faster electrochemical kinetics, with a diffusion-limited current plateau, compared to the surrounding sample points. The analysis of the electrochemical current suggests that the defects are equivalent to disk-shaped defects with radii of tens of nanometers, or to one-dimensional defects with nanometer to sub-nanometer widths. These results demonstrate that we can effectively isolate and electrochemically amplify the response from individual defects on a sample surface using SECCM, revealing features below the optical diffraction limit that would normally require high-resolution electron microscopy or scanning tunneling microscopy to detect.
Permanent Link: https://hdl.handle.net/11104/0332544