One dimensional nanomaterials such as nanorods (NRs), nanowires (NWs), nanobelts and nanotubes (NTs) have attracted increasing attentions over the past two decades due to their shape dependent chemical and physical properties.

Tellurium (Te) is a narrow direct band gap semiconducting material with band gap of ~0.35 eV at room temperature. Crystalline Te displays physical properties including photoconductivity and thermoelectric properties. Considerable efforts have been made to synthesize the Te nanostructures. Solution-based approaches such as hydrothermal or solvothermal method has been regarded as a low-cost and large-scale preparation method for nanomaterials.

As the crucial factors for the formation of Te nanomaterials are not clear, it is of great importance to seek optimal conditions, fabricate ultra-uniform nanostructures and understand the growth mechanism for designing the fabricating routes.

A Chinese research team led by Prof. FEI Guangtao from Institute of Solid State Physics, Hefei Institutes of Physical Science of Chinese Academy of Sciences reported a facile route to realize controllable synthesis of Te nanostructures in large quantity by a solvothermal process. The study was published in CrystEngComm.

In this study, poly (vinyl pyrrolidone) (PVP) serves as surfactant while ascorbic acid aqueous solution (AAAS) as reducing agent. By adjusting the amounts of the surfactant and reducing agent, researchers prepared ultra-thin Te NWs, NTs and trifold NRs. The diameter of the Te NWs and NTs is 30–40 nm and 120–150 nm, respectively.

They then presented a morphology evolution diagram based on different amounts of PVP and AAAS and investigated meticulously the effects of temperature.

After that, they discussed the growth mechanism of the Te NTs and trifold Te NRs based on the crystallization law.

This study showed the morphology evolution of the Te nanostructures prepared at 120 C, 150 C and 180 C, respectively, as well as the schematic diagram of crystal structure of Te and the growth route of the Te NTs and trifold Te NRs.

This work was supported by National Basic Research Program of China (973 Program), the National Natural Science Foundation of China, the CAS/SAFEA International Partnership Program for Creative Research Teams, and the Foundation of Director of Institute of Solid State Physics, the Chinese Academy of Sciences.

Figure: Schematic growth route of the Te NTs and trifold Te NRs. (a) amorphous Te in initial stage; (b) initial seed of the Te NTs; (c) middle product of the Te NTs; (d) final crystal of the Te NTs; (e) initial seed of the trifold Te NRs; (f) middle product of the trifold Te NRs; (g) final crystal of the trifold Te NRs. (Image by ZHONG Binnian)