Large scale synthesis of uniform CuS nanotubes in ethylene glycol by a sacrificial templating method under mild conditions

Uniform CuS nanotubes of 30-90 nm in inner diameter and 20-50 nm in thickness, can be synthesized in large quantities by a facile solution reaction at 80 degrees C in ethylene glycol using Cu nanowires as sacrificial templates and choosing suitable sulfur sources for the sulfuration reaction, where suitable sulfur sources and solvent played crucial roles in the formation of well-defined CuS nanotubes. The results demonstrated that suitable sulfur sources such as thiourea and thiacetamide which release ionic sulfur rather than molecular sulfur at their decomposition temperature are favorable for the formation of CuS nanotubes, in contrast to sulfur powders. Further treatment of the product at higher temperature (140 degrees C) can improve the crystallinity but results in a slight shrinking of the nanotubes toward the inner side. In addition, the similar reaction in water media cannot produce such nanotubes. The shape evolution process and the formation mechanism of CuS nanotubes as well as the thermal stability of these nanotubes were studied.