A new approach to obtain calcium cobalt oxide by microwave-assisted hydrothermal synthesis

Autor(es)

Medina, M. S. ^{[1, 2]} ; Bernardi, J. C. ^[1] ; Zenatti, A. ^[1] ; Escote, M. T. ^[1]

Afiliação do(s) autor(es)

^[1] Fed Univ ABC, Ctr Engn Modeling & Appl Social Sci, UFABC, Santo Andre, SP - Brazil

^[2] Energy & Nucl Res Inst, Ctr Sci & Technol Mat, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CERAMICS INTERNATIONAL; v. 46, n. 2, p. 1596-1600, FEB 1 2020.
• Citações Web of Science: 0

Resumo

This study describes the effect of microwave-assisted hydrothermal synthesis on the crystalline phase-formation, microstructural characteristics, and thermoelectric performance of Ca3Co4O9. Synthesis parameters, such as time, temperature, KOH concentration, and oxidation states of Co ions, to produce this compound, were studied. X-ray diffraction and X-ray photoelectron spectroscopy showed that the most critical parameters for the phase formation are the oxidation states of Co ions. Ca3Co4O9 can be obtained by microwave-assisted hydrothermal synthesis at 503 K for 30 min and thermal treatment at 1173 K for 120 min. Scanning electron microscopy images showed that the sample exhibits randomly oriented particles with plate-like morphology and range size between 0.4 and 1.2 mu m. From measurements of electrical resistivity, thermal conductivity, and Seebeck coefficient, we obtained a figure of merit of similar to 0.008 at 300 K. (AU)

• Processo FAPESP: 16/03575-2 - Transporte elétrico de nanoestruturas dos compostos RNiO3
• Beneficiário: Márcia Tsuyama Escote
• Modalidade de apoio: Auxílio à Pesquisa - Regular