Chemically exfoliated ReS2 nanosheets.

The production of two-dimensional rhenium disulfide (ReS2) nanosheets by exfoliation using lithium intercalation is demonstrated. The vibrational and photoluminescence properties of the exfoliated nanosheets are investigated, and the local atomic structure is studied by scanning and transmission electron microscopy. The catalytic activity of the nanosheets in a hydrogen evolution reaction (HER) is also investigated. The electrochemical properties of the exfoliated ReS2 nanosheets include low overpotentials of ∼100 mV and low Tafel slopes of 75 mV dec(-1) for HER and are attributed to the atomic structure of the superlattice 1T' phase. The presence of bandgap photoluminescence demonstrates that the nanosheets retain their semiconducting nature. ReS2 nanosheets produced by this method provide unique photocatalytic properties that are superior to those of other two-dimensional systems.