Influence of the reducing agent on the formation and morphology of the bismuth telluride nanostructures by using template assisted chemical process: From nanowires to ultrathin nanotubes

Abstract

One-dimensional telluride based materials have recently attracted significant attention for development of the high-efficiency thermoelectric materials. Among one dimensional nanostructures, nanotubular structure has shown significant enhancement in the energy conversion efficiency due to higher reduction in the therml conductivity as compared to other one dimensional nanostructrues. Though some progress has already been establsihed to prepare nanotubes still synthesis of ultra-thin, smoother surface and stoichiometry Bi2Te3 nanotubes are still big challenges. Herein, we have reported that properly adjusting concentration of the reducing agent, different types of one-dimensional Bi2Te3 nanostructures such as nanowires to hollow nanostructures can be synthesized by using a template assisted chemical process. Furthermore, ultra-thin, smoother surface and close to stoichiometry Bi2Te3 nanotubes with a diameter of about 50 nm have been obtained by properly adjusting concentration of the reducing agent. Our experimental results evidenced that concentration of the reducing agent (hydrazine hydrate) plays a crucial role (morphology controlling agent) for synthesis of different types one-dimensional nanostructures from nanowires to ultrathin smooth surface nanotubes. A possible formation mechanism has been proposed to explain formation of the different one-dimensional Bi2Te3 nanostructures and the specific role of the reducing agent based on the experimental results.