Ultra-long WSe2 nanotubes and related hybrid nanostructures

Abstract

Millimeter-long WSe2 nanotubes were synthesized via continuous selenidation of ultralong W18O49 nanowhiskers. A modified reactor configuration enabling a sustained selenium vapor supply allowed complete conversion of oxide nanowhiskers into hollow WSe2 nanotubes with lengths reaching hundreds of micrometers to millimeters, 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 ultralong WSe2 nanotubes and hybrid structures offer a versatile platform for optoelectronic, photonic, and catalytic applications.