Mapping Electron Transfer at MoS2 Using Scanning Electrochemical Microscopy

Understanding the role of macroscopic and atomic defects in the interfacial electron transfer properties of layered transition metal dichalcogenides is important in optimizing their performance in energy conversion and electronic devices. Means of determining the heterogeneous electron transfer rate...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1999. - 34(2018), 46 vom: 20. Nov., Seite 13864-13870
1. Verfasser: Ritzert, Nicole L (VerfasserIn)
Weitere Verfasser: Szalai, Veronika A, Moffat, Thomas P
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2018
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, U.S. Gov't, Non-P.H.S. Research Support, Non-U.S. Gov't
Beschreibung
Zusammenfassung:Understanding the role of macroscopic and atomic defects in the interfacial electron transfer properties of layered transition metal dichalcogenides is important in optimizing their performance in energy conversion and electronic devices. Means of determining the heterogeneous electron transfer rate constant, k, have relied on the deliberate exposure of specific electrode regions or additional surface characterization to correlate proposed active sites to voltammetric features. Few studies have investigated the electrochemical activity of surface features of layered dichalcogenides under the same experimental conditions. Herein, MoS2 flakes with well-defined features were mapped using scanning electrochemical microscopy (SECM). At visually flat areas of MoS2, k of hexacyanoferrate(III) ([Fe(CN)6]3-) and hexacyanoferrate(II) ([Fe(CN)6]4-) was typically smaller and spanned a larger range than that of hexaammineruthenium(III) ([Ru(NH3)6]3+), congruent with the current literature. However, in contrast to previous studies, the reduction of [Fe(CN)6]3- and the oxidation of [Fe(CN)6]4- exhibited similar rate constants, attributed to the dominance of charge transfer through surface states. The comparison of SECM with optical and atomic force microscopy images revealed that while most of the flake was electroactive, edge sites associated with freshly exposed areas that include macrosteps consisting of several monolayers as well as recessed areas exhibited the highest reactivity, consistent with the reported results
Beschreibung:Date Completed 25.01.2019
Date Revised 11.10.2023
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.8b02731