  During the synthesis of heterostructured nanomaterials, unwanted structural
and morphological changes in nanostructures may occur, especially when multiple
sequential growth steps are involved. In this study, we describe a synthesis
strategy of heterostructured ZnS/Al2O3/MoS2 core-shell nanowires (NWs), and
explore the role of the Al2O3 interlayer during synthesis. Core-shell NWs were
produced via a four-step route: 1) synthesis of ZnO NWs on a silicon wafer, 2)
deposition of thin Al2O3 layer by ALD, 3) magnetron deposition of MoO3 layer,
and 4) annealing of the sample in the sulphur atmosphere. During
sulphurization, ZnO is converted into ZnS, and MoO3 into MoS2, while the Al2O3
interlayer preserves the smooth surface of an NW required for the growth of a
continuous MoS2 shell. The resulting ZnS/Al2O3/MoS2 core-shell NWs were
characterized by transmission electron microscopy, X-ray diffraction and
photoelectron spectroscopy, Raman spectroscopy, and optical photoluminescence
spectroscopy. A reported strategy can be used for the synthesis of other
core-shell NWs with a transition metal dichalcogenides (TMDs) shell to protect
the NW core material that may otherwise be altered or damaged by the reactive
chalcogenides at high temperatures.
