Rapid Joule-Heating Synthesis for Manufacturing High-Entropy Oxides as Efficient Electrocatalysts.

High-entropy oxide (HEO) including multiple principal elements possesses great potential for various fields such as basic physics, mechanical properties, energy storage, and catalysis. However, the synthesis method of high-entropy compounds through the traditional heating approach is not conducive to the rapid properties screening, and the current elemental combinations of HEO are also highly limited. Herein, we report a rapid synthesis method for HEO through the Joule-heating of nickel foil with dozens of seconds. High-entropy rocksalt oxides (HERSO) with the new elemental combination, high-entropy spinel oxides (HESO), and high-entropy perovskite oxide (HEPO) have been synthesized through the Joule-heating. The synthesized HERSO with new elemental combinations proves to be a great promotion of OER activity due to the synergy of multiple components and the continuous electronic structure experimentally and theoretically. The demonstrated synthesis approach and the new component combination of HERSO provide a broad platform for the development of high-entropy materials and catalysts.