BixZnCo2-xO4(0 =x= 0.2) nanoparticles with differentxvalues have been prepared by the sol-gel method; the structural, morphological, thermal and thermoelectric properties of the prepared nanomaterials are investigated. XRD analysis confirms that Bi is completely dissolved in the ZnCo2O4lattice till thexvalues of =0.1 and the secondary phase of Bi2O3is formed at higherxvalue (x> 0.1). The synthesized nanomaterials are densified and the thermoelectric properties are studied as a function of temperature. The electrical resistivity of the BixZnCo2-xO4decreased withxvalue and it fell to 4 × 10-2O m for the sample withxvalue = 0.1. The Seebeck coefficient value increased with the increase of Bi substitution till thexvalue of 0.1 and decreased for the sample with higher Bi content (x= 0.2) as the resistivity of the sample increased due to secondary phase formation. With the optimum Seebeck coefficient and electrical resistivity, Bi0.1ZnCo1.9O4shows the high-power factor (a2s550 K) of 2.3 µW K-2m-1and figure of merit of 9.5 × 10-4at 668 K respectively, compared with other samples. The experimental results reveal that Bi substitution at the Co site is a promising approach to improve the thermoelectric properties of ZnCo2O4.
ASJC Scopus subject areas
- Chemical Engineering(all)