Solution combustion synthesis of high-entropy metal spinel oxide as oxygen evolution reaction catalyst

High-entropy metal spinel oxide (HEO) is proved to be a promising oxygen evolution reaction (OER) catalyst with high catalytic performance and stability. A short routine synthesis process based on solution combustion was proposed prepare (Co0.25Ni0.25Mn0.25Zn0.25)Fe2O4 HEO in this work. During the process, products were rapidly synthesized melted due high-temperature reaction, then quickly crystallized surface of nickel foam form nano-structure coating. With aid nano-scale structure, overpotential non-activation electrode reaches 276 mV at current density 10 mA·cm−2, after 100 h i-t test, it can further reduced 230 mV, which proves activity OER catalysis. The promotion attributed reconstruction caused by selective element leaching boost vacancy, leading formation flocculation around core long-term process. This work indicates special casting for functional materials explores application rapid crystallization.