AUTHOR=Schweidler Simon , Tang Yushu , Lin Ling , Karkera Guruprakash , Alsawaf Alaa , Bernadet Lucile , Breitung Ben , Hahn Horst , Fichtner Maximilian , Tarancón Albert , Botros Miriam 

TITLE=Synthesis of perovskite-type high-entropy oxides as potential candidates for oxygen evolution

JOURNAL=Frontiers in Energy Research

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.983979

DOI=10.3389/fenrg.2022.983979

ISSN=2296-598X

ABSTRACT=<p>High-entropy materials offer a wide range of possibilities for synthesizing new functional ceramics for different applications. Many synthesis methods have been explored to achieve a single-phase structure incorporating several different elements, yet a comparison between the synthesis methods is crucial to identify the new dimension such complex ceramics bring to material properties. As known for ceramic materials, the synthesis procedure usually has a significant influence on powder morphology, elemental distribution, particle size and powder processability. Properties that need to be tailored according to specific applications. Therefore, in this study perovskite-type high-entropy materials (Gd<sub>0.2</sub>La<sub>0.2–<italic>x</italic></sub>Sr<sub><italic>x</italic></sub>Nd<sub>0.2</sub>Sm<sub>0.2</sub>Y<sub>0.2</sub>) (Co<sub>0.2</sub>Cr<sub>0.2</sub>Fe<sub>0.2</sub>Mn<sub>0.2</sub>Ni<sub>0.2</sub>)O<sub>3</sub> (<italic>x</italic> = 0 and <italic>x</italic> = 0.2) are synthesized for the first time using mechanochemical synthesis and a modified Pechini method. The comparison of different syntheses allows, not only tailoring of the constituent elements of high-entropy materials, but also to optimize the synthesis method as needed to overcome limitations of conventional ceramics. To exploit the novel materials for a variety of energy applications, their catalytic activity for oxygen evolution reaction was characterized. This paves the way for their integration into, e.g., regenerative fuel cells and metal air batteries.</p>