Lawrence Berkeley National Laboratory
Photocatalytic Stability of Single- and Few-Layer MoS2
- Author(s): Parzinger, E
- Miller, B
- Blaschke, B
- Garrido, JA
- Ager, JW
- Holleitner, A
- Wurstbauer, U
- et al.
Published Web Locationhttps://doi.org/10.1021/acsnano.5b04979
© 2015 American Chemical Society. MoS2crystals exhibit excellent catalytic properties and great potential for photocatalytic production of solar fuels such as hydrogen gas. In this regard, the photocatalytic stability of exfoliated single- and few-layer MoS2immersed in water is investigated by μ-Raman spectroscopy. We find that while the basal plane of MoS2can be treated as stable under photocatalytic conditions, the edge sites and presumably also defect sites are highly affected by a photoinduced corrosion process. The edge sites of MoS2monolayers are significantly more resistant to photocatalytic degradation compared to MoS2multilayer edge sites. The photostability of MoS2edge sites depends on the photon energy with respect to the band gap in MoS2and also on the presence of oxygen in the electrolyte. These findings are interpreted in the framework of an oxidation process converting MoS2into MoOxin the presence of oxygen and photoinduced charge carriers. The high stability of the MoS2basal plane under photocatalytic treatment under visible light irradiation of extreme light intensities on the order of P ≈ 10 mW/μm2substantiates MoS2's potential as photocatalyst for solar hydrogen production.