文摘
MoS<sub>2sub> crystals 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 MoS<sub>2sub> immersed in water is investigated by 渭-Raman spectroscopy. We find that while the basal plane of MoS<sub>2sub> can 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 MoS<sub>2sub> monolayers are significantly more resistant to photocatalytic degradation compared to MoS<sub>2sub> multilayer edge sites. The photostability of MoS<sub>2sub> edge sites depends on the photon energy with respect to the band gap in MoS<sub>2sub> and also on the presence of oxygen in the electrolyte. These findings are interpreted in the framework of an oxidation process converting MoS<sub>2sub> into MoO<sub>xsub> in the presence of oxygen and photoinduced charge carriers. The high stability of the MoS<sub>2sub> basal plane under photocatalytic treatment under visible light irradiation of extreme light intensities on the order of P 鈮?10 mW/渭m<sup>2sup> substantiates MoS<sub>2sub>鈥檚 potential as photocatalyst for solar hydrogen production.