  Van der Waals (vdW) layered materials have drawn tremendous interests due to
their unique properties. Atom intercalation in the vdW gap of layered materials
can tune their electronic structure and generate unexpected properties. Here we
report a chemical-scissor mediated method that enables metal intercalation into
transition metal dichalcogenides (TMDCs) in molten salts. By using this
approach, various guest metal atoms (Mn, Fe, Co, Ni, Cu, and Ag) were
intercalated into various TMDCs hosts (such as TiS2, NbS2, TaS2, TiSe2, NbSe2,
TaSe2 and Ti0.5V0.5S2). The structure of the intercalated compound and
intercalation mechanism was investigated. The results indicate that the vdW gap
and valence state of TMDCs can be modified through metal intercalation, and the
intercalation behavior is dictated by the electron work function. Such a
chemical-scissor mediated intercalation provides an approach to tune the
physical and chemical properties of TMDCs, which may open an avenue in
functional application ranging from energy conversion to electronics.
