  2D Janus TMDC layers with broken mirror symmetry exhibit giant Rashba
splitting and unique excitonic behavior. For their 1D counterparts, the Janus
nanotubes possess curvature, which introduce an additional degree of freedom to
break the structural symmetry. This could potentially enhance these effects or
even give rise to novel properties. In addition, Janus MSSe nanotubes (M=W,
Mo), with diameters surpassing 4 nm and Se positioned externally, consistently
demonstrate lower energy states than their Janus monolayer counterparts.
However, there have been limited studies on the preparation of Janus nanotubes,
due to the synthesis challenge and limited sample quality. Here we first
synthesized MoS2 nanotubes based on SWCNT-BNNT heterostructure and then
explored the growth of Janus MoSSe nanotubes from MoS2 nanotubes with the
assistance of H2 plasma at room temperature. The successful formation of the
Janus structure was confirmed via Raman spectroscopy, and microscopic
morphology and elemental distribution of the grown samples were further
characterized. The synthesis of Janus MoSSe nanotubes based on SWCNT-BNNT
enables the further exploration of novel properties in Janus TMDC nanotubes.
