Alagar Nedunchezhian AS, Sidharth D, Rajkumar R, Yalini Devi N, Maeda K, Arivanandhan M, Fujiwara K, Anbalagan G, Jayavel R. Enhancing the thermoelectric power factor of nanostructured ZnCo
2O
4 by Bi substitution.
RSC Adv 2020;
10:18769-18775. [PMID:
35518284 PMCID:
PMC9054002 DOI:
10.1039/d0ra01542c]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 05/11/2020] [Indexed: 11/21/2022] Open
Abstract
BixZnCo2−xO4 (0 ≤ x ≤ 0.2) nanoparticles with different x values 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 ZnCo2O4 lattice till the x values of ≤0.1 and the secondary phase of Bi2O3 is formed at higher x value (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−xO4 decreased with x value and it fell to 4 × 10−2 Ω m for the sample with x value ≤ 0.1. The Seebeck coefficient value increased with the increase of Bi substitution till the x value 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, Bi0.1ZnCo1.9O4 shows the high-power factor (α2σ550 K) of 2.3 μW K−2 m−1 and figure of merit of 9.5 × 10−4 at 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.
Nanostructuring and Bi substitution have considerably increased the thermoelectric power factor and ZT of BixZnCo2−xO4; Bi1.9ZnCo1.9O4 shows a higher power factor than that of other Bi substituted samples.![]()
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