Dispersibility, stabilization, and chemical stability of ultrathin tellurium nanowires in acetone: Morphology change, crystallization, and transformation into TeO2 in different solvents
ABSTRACT The dispersibility and stabilization of freshly synthesized ultrathin tellurium nanowires with diameters of 4-9 nm using poly(vinyl pyrrolidone) (PVP) as a capping agent can be well controlled through an easy acetone-addition process. Ultrathin Te nanowires synthesized by a hydrothermal method using PVP as a capping agent will aggregate in a water/acetone system, and their aggregation state strongly relies on the volume of water and acetone in this mixed solution. This phenomenon is due to the different solubility of PVP in water and acetone, which has significant influence on the dispersibility and stabilization of the nanowires. The results also demonstrate that the freshly prepared Te nanowires are not stable after being stored for a prolonged time in contact with air, ethanol, and water. Ultrathin Te nanowires can be oxidized easily with various final morphologies, which are core-shell structures in contact with air, amorphous nanoparticles and nanoplatelets in ethanol, and large square flakes in water. The entire conversion process from crystalline Te nanowires to amorphous TeO2 nanoparticles or single-crystal paratellurite (TeO2) at room temperature was carefully studied, implying that tellurium nanowires synthesized by other chemical methods and other nanomaterials after synthesis could also not be stable, and their storage methods require special attention.
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ABSTRACT: A one-dimensional (1D) hollow hierarchical tellurium nanostructure composed of single crystalline tube and polycrystalline spheres has been fabricated by a simple microwave-assisted solution process in the presence of trisodium citrate. A self-sacrificed template eroding mechanism combined with a surface assembly process is deduced and discussed in detail.RSC Advances 08/2014; 4(68). DOI:10.1039/C4RA04962D · 3.71 Impact Factor
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ABSTRACT: Thermoelectrics is a challenging issue for future energy harvesting and cooling technology. We here have demonstrated a new system of the tellurium nanowire (TeNW) films hybridized with single-walled carbon nanotube (SWCNT) as a flexible thermoelectric material and investigated their thermoelectric properties as a function of SWCNT weight ratio in the hybrid. The excellent mechanical stability and electrical conductivity of SWCNT enhance the flexibility and thermoelectric properties of the pure TeNW film. The addition of 2 wt% SWCNT into TeNW matrix significantly increases the electrical conductivity from 4 to 50 S m−1 while maintaining the high thermopower, thereby leading to one order of magnitude higher figure of merit (ZT) compared to the pure TeNW film. These results indicate that the SWCNT/TeNW hybrid film would be promising for a potential use as a flexible thermoelectric material.Synthetic Metals 12/2014; 198:340-344. DOI:10.1016/j.synthmet.2014.10.037 · 2.22 Impact Factor
Nano Research 01/2014; DOI:10.1007/s12274-014-0586-9 · 6.96 Impact Factor