Nanoscale redox mapping at the MoS<sub>2</sub>-liquid interface.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33637747.
- Also identified by DOI 10.1038/s41467-021-21660-z and PMC identifier 7910562.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Layered MoS<sub>2</sub> is considered as one of the most promising two-dimensional photocatalytic materials for hydrogen evolution and water splitting; however, the electronic structure at the MoS<sub>2</sub>-liquid interface is so far insufficiently resolved. Measuring and understanding the band offset at the surfaces of MoS<sub>2</sub> are crucial for understanding catalytic reactions and to achieve further improvements in performance. Herein, the heterogeneous charge transfer behavior of MoS<sub>2</sub> flakes of various layer numbers and sizes is addressed with high spatial resolution in organic solutions using the ferrocene/ferrocenium (Fc/Fc<sup>+</sup>) redox pair as a probe in near-field scanning electrochemical microscopy, i.e. in close nm probe-sample proximity. Redox mapping reveals an area and layer dependent reactivity for MoS<sub>2</sub> with a detailed insight into the local processes as band offset and confinement of the faradaic current obtained. In combination with additional characterization methods, we deduce a band alignment occurring at the liquid-solid interface.