Improved synthesis of WS2 nanotubes with relatively small diameters by tuning sulfurization timing and reaction temperature

Improvement of synthesis techniques of tungsten disulfide (WS2) nanotubes is of great importance for understanding of the physical properties of WS2 nanotubes and their applications. Previously, relatively small diameter WS2 nanotubes were synthesized using solvothermally synthesized nanowires as precursors. The obtained samples exhibited relatively uniform nanotube structures, but in the samples, there were a lot of degraded nanoparticles and nanoflakes as by-products. Here, we demonstrate that such by-products can be well removed by tuning the sulfurization timing and precise control of the reaction temperature. WS2 nanotubes with relatively small diameters are well produced without such by-products.