Simple approach to synthesize CNTs uniformly coated Bi < inf > 2 < /inf > Te < inf > 3 < /inf > nanocomposites by mechanical alloying

Abstract

One-dimensional nanocomposite containing multiwall carbon nanotubes (MWCNTs) and thin bismuth tellurite (Bi2Te3) nanotubes have been synthesized using ball-milling process. The primary focus of this work is to study the morphological, molecular bonding, and structure of the novel nanocomposite and to explore the underlying mechanism to synthesize a novel nanocomposite for thermoelectric applications. The experimental results from the high-resolution TEM revealed that MWCNTs are uniformly coated on the surface of the Bi2Te3 nanotubes consisting of a bundle of two. Furthermore, it indicated that minimal strain is present at the interface between MWCNTs and Bi2Te3 nanotubes which can add additional lattice scattering, and hence, the lattice contribution to the thermal conductivity can be further reduced due to phonon-blocking phenomena. Analytical analysis results further indicated that the MWCNTs incorporated in the nanocomposites showed less disorder and successfully formation of the nanocomposites. We believe that our approach provides the advantages of simplicity, efficient and opens a new way to prepare a novel 1D thermoelectric nanocomposite which can further improve the thermophysical properties for future energy-harvesting applications and thermoelectric devices.