Colloidal
Synthesis of Single-Layer MSe<sub>2</sub> (M = Mo, W) Nanosheets via
Anisotropic Solution-Phase Growth Approach
- Publication date
- Publisher
Abstract
The generation of single-layer 2-dimensional
(2D) nanosheets has
been challenging, especially in solution-phase, since it requires
highly anisotropic growth processes that exclusively promote planar
directionality during nanocrystal formation. In this study, we discovered
that such selective growth pathways can be achieved by modulating
the binding affinities of coordinating capping ligands to the edge
facets of 2D layered transition-metal chalcogenides (TMCs). Upon changing
the functional groups of the capping ligands from carboxylic acid
to alcohol and amine with accordingly modulated binding affinities
to the edges, the number of layers of nanosheets is controlled. Single-layer
MSe<sub>2</sub> (M = Mo, W) TMC nanosheets are obtained with the use
of oleic acid, while multilayer nanosheets are formed with relatively
strong binding ligands such as oleyl alcohol and oleylamine. With
the choice of appropriate capping ligands in the 2D anisotropic growth
regime, our solution-based synthetic method can serve a new guideline
for obtaining single-layer TMC nanosheets