Mechanochemistry for Energy Materials: Impact of High-Energy Milling on Chemical, Electric and Thermal Transport Properties of Chalcopyrite CuFeS 2 Nanoparticles

• Published in: ChemistryOpen (Weinheim) Vol. 10; no. 8; pp. 806 - 814
• Main Authors: Baláž, Peter, Dutková, Erika, Baláž, Matej, Džunda, Róbert, Navrátil, Jiří, Knížek, Karel, Levinský, Petr, Hejtmánek, Jiří
• Format: Journal Article
• Language: English
• Published: Germany 01.08.2021
• Subjects: energy materials; mechanochemistry; thermoelectrics; semiconductors; chalcopyrite
• ISSN: 2191-1363; 2191-1363
• DOI: 10.1002/open.202100144

Chalcopyrite CuFeS , a semiconductor with applications in chemical sector and energy conversion engineering, was synthetized in a planetary mill from elemental precursors. The synthesis is environmentally friendly, waste-free and inexpensive. The synthesized nano-powders were characterized by XRD, SEM, EDX, BET and UV/Vis techniques, tests of chemical reactivity and, namely, thermoelectric performance of sintered ceramics followed. The crystallite size of ∼13 nm and the strain of ∼17 were calculated for CuFeS powders milled for 60, 120, 180 and 240 min, respectively. The evolution of characteristic band gaps, Eg, and the rate constant of leaching, k, of nano-powders are corroborated by the universal evolution of the parameter S /X (S -specific surface area, X-crystallinity) introduced for complex characterization of mechanochemically activated solids in various fields such as chemical engineering and/or energy conversion. The focus on non-doped semiconducting CuFeS enabled to assess the role of impurities, which critically and often negatively influence the thermoelectric properties.