Preparation of metal chalcogenides
A method embodiment involves preparing single metal or mixed transition metal chalcogenide using exfoliation of two or more different bulk transition metal dichalcogenides in a manner to form an intermediate hetero-layered transition metal chalcogenide structure, which can be treated to provide a single-phase transition metal chalcogenide.
1. A transition metal chalcogenide material having an as-ball milled hetero-layered structure having layers of different composition exfoliated from different starting transition metal chalcogenides by ball milling the different starting transition metal chalcogenides together wherein individual layers of the as-ball milled hetero-layered structure are chemically un-modified relative to the different starting transition metal chalcogenides.
2. The material of claim 1 that has been converted to comprise a substantially homogeneous solid solution of two or more different transition metal chalcogenides.
3. The material of claim 1 wherein respective layers have at least one of a different transition metal constituent and a chalcogen constituent from the next adjacent layer.
4. The material of claim 1 where the hetero-layered structure comprises transition metal dichalcogenide layers with different transition metal constituents.
5. The material of claim 1 wherein the hetero-layered structure comprises transition metal trichalcogenide layers having different transition metal constituents.
6. The material of claim 1 wherein the hetero-layered structure comprises transition metal dichalcogenide layers having different chalcogen constituents.
7. The material of claim 1 wherein the hetero-layered structure comprises transition metal trichalcogenide layers having different chalcogen constituents.
8. The material of claim 1 wherein each of the layers includes a transition metal that is selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Mo, W, Re, Pd, Pt, In, Ga and Sn.
9. The material of claim 1 which includes at least one of graphite, black phosphorus, and boron nitride.
10. The material of claim 2 which has been heated to convert the structure to a single-phase structure.
11. The material of claim 1 wherein the layers of the as-ball milled hetero-layered structure are self-assembled by the ball milling.
12. The material of claim 8 having a chemical composition represented by (M a M 2 b M 3 c . . . n )(X d X 2 e X 3 f ), where the formula unit includes two or more different transition metals (M), and X, X 2 and X 3 represent S, Se, or Te, whereby the sum of a+b+c+. . . n is between 1 and 3 and the sum of d+e+f is between 1 and 6.