Epitaxial Assembly and Spectroscopic Inspection of Core–Shell WS₂@WSe₂ Nanotubes

1D multiwall tungsten disulfide nanotubes were discovered more than three decades ago, and their large-scale fabrication has been worked out systematically over the years. Building on this knowledge, reports on the more complex core–shell nanotubular structures have emerged in recent years. In the present work, core–shell tungsten disulfide and tungsten diselenide nanotubes (WS2@WSe2 NTs) have been materialized through high-temperature selenidation of WS2 nanotubes and fine WO3 powder, yielding large quantities of epitaxially aligned heterostructures. Advanced high-resolution electron microscopy revealed the formation of complex heterointerfaces with well-defined atomic arrangements between the constituent phases. Optical characterization shows distinctive electronic properties arising from the heterostructure architecture, indicating strong interfacial coupling between the WS2 and WSe2 constituents. The unique electronic and structural characteristics of these nanotubes position them as promising candidates for enhanced photocatalytic applications and quantum device integration, where precise control over electronic states and charge transfer dynamics is critical.