Nanoscale redox mapping at the MoS2-liquid interface.
He-Yun DuYi-Fan HuangDeniz WongMao-Feng TsengYi-Hsin LeeChen-Hao WangCheng-Lan LinGermar HoffmannKuei-Hsien ChenLi-Chyong ChenPublished in: Nature communications (2021)
Layered MoS2 is considered as one of the most promising two-dimensional photocatalytic materials for hydrogen evolution and water splitting; however, the electronic structure at the MoS2-liquid interface is so far insufficiently resolved. Measuring and understanding the band offset at the surfaces of MoS2 are crucial for understanding catalytic reactions and to achieve further improvements in performance. Herein, the heterogeneous charge transfer behavior of MoS2 flakes of various layer numbers and sizes is addressed with high spatial resolution in organic solutions using the ferrocene/ferrocenium (Fc/Fc+) 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 MoS2 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.
Keyphrases
- quantum dots
- reduced graphene oxide
- room temperature
- visible light
- high resolution
- ionic liquid
- highly efficient
- transition metal
- gold nanoparticles
- single molecule
- photodynamic therapy
- optical coherence tomography
- high density
- pseudomonas aeruginosa
- label free
- biofilm formation
- water soluble
- tandem mass spectrometry
- fluorescent probe