Ultra-long WSe2 nanotubes and related hybrid nanostructures

Abstract

Ultra-long WSe₂ nanotubes were synthesized via continuous selenidation of ultra-long W₁₈O₄₉ nanowhiskers. A modified reactor configuration enabling a sustained selenium vapor supply allowed complete conversion of the oxide nanowhiskers into hollow WSe₂ nanotubes with lengths reaching hundreds of micrometers, while keeping diameters below 100 nm. Detailed structural characterization confirmed the multilayered 2H-WSe₂ structure and hollow morphology. Controlling the reaction time enables the synthesis of both hybrid W₁₈O₄₉@WSe₂ core–shell nanowhiskers and 1D/2D nanotube–plate hybrid structures. Optical characterization revealed excitonic emission and polariton-related optical features arising from light confinement within the nanotube cavity. Electrical measurements on single-nanotube devices demonstrated semiconducting behavior with nonlinear I–V characteristics and a clear photoresponse under laser illumination. Together, these ultra-long WSe₂ nanotubes and hybrid structures offer a versatile platform for optoelectronic, photonic, and catalytic applications.