Preparation of MoS2 Nanosheets. MoS2 nanosheets were produced
by the electrochemical intercalation and exfoliation
method recently reported by our group.27 The lithium intercalation
was performed in a test cell using the Li foil as anode
and 1MLiPF6 as electrolyte, which was dissolved in a mixture of
ethyl carbonate (EC) and dimethyl carbonate (DMC) with a
volume ratio of 1:1. The bulk MoS2 powder (2 mg) mixed with
acetylene black and poly(vinylidene fluoride) (PVDF) binder
dispersed in N-methylpyrrolidone (NMP) was used as cathode.
In the mixed slurry, the mass ratio of MoS2, acetylene black, and
PVDF was 80:10:10. The resulting slurry was then uniformly
coated on a copper foil and dried under vacuum overnight. The
electrochemical intercalation of the layered materials in the
test cell was accomplished in a Neware battery test system at
room temperature. The electrochemical intercalation was performed
using the galvanostatic discharge at current density of
0.025 mA. After the discharge process, the Li-intercalated
sample (prepared from 2 mg MoS2) was washed with acetone
to remove any residual electrolyte (LiPF6), followed by exfoliation
and ultrasonication in 20 mL distilled water to obtain the
0.1 mg mL1 MoS2 solution.