Facile large scale synthesis of WS 2 nanotubes from WO 3 nanorods prepared by a hydrothermal route

Abstract

Hexagonal WO 3 nanorods of 5–50 nm in diameter and 150–250 nm in length have been synthesised in gram quantities by a low temperature hydrothermal route using citric acid as a structural modifier and hexadecylamine as a templating agent. The ratio of [A]/[W] play an important role on WO 3 nanorods formation. These WO 3 nanorods were found highly suitable as a precursor for the synthesis of a good yield of multiwalled WS 2 nanotubes by reducing them with H 2S at 840 °C for 30 min. The length and the wall thickness of the WS 2 nanotubes could be altered by controlled reduction of the oxide precursor. The morphology, structure and the composition of the WO 3 nanorods and WS 2 nanotubes were characterised by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX) and by selected area electron diffraction techniques (SAED).