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.