Toward nanostructured thermoelectrics: Synthesis and characterization of lead telluride gels and aerogels

Shreyashi Ganguly, Stephanie L. Brock

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

The synthesis and characterization of lead telluride (PbTe) gels and aerogels with nanostructured features of potential benefit for enhanced thermoelectrics is reported. In this approach, discrete thiolate-capped PbTe nanoparticles were synthesized by a solution-based approach followed by oxidation-induced nanoparticle assembly with tetranitromethane or hydrogen peroxide to form wet gels. Drying of the wet gels by supercritical CO 2 extraction yielded aerogels, whereas xerogels were produced by ambient pressure bench top drying. The gels consist of an interconnected network of colloidal nanoparticles and pores with surface areas up to 74 m2 g-1. The thermal stability of the nanostructures relative to nanoparticles was probed with the help of in situ transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The aerogels were observed to sublime at a higher temperature and over a larger range (425-500 °C) relative to the precursor nanoparticles. TGA-DSC suggests that organic capping groups can be removed in the region 250-450 °C, and melting of PbTe nanoparticles occurs near the temperature for bulk materials (ca. 920 °C). The good thermal stability combined with the presence of nanoscale interfaces suggests PbTe gels may show promise in thermoelectric devices.

Original languageEnglish (US)
Pages (from-to)8800-8806
Number of pages7
JournalJournal of Materials Chemistry
Volume21
Issue number24
DOIs
StatePublished - Jun 28 2011

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