Precise Cooling Time Control in Joule Heating for Efficient Oxygen Evolution Reaction of High-Entropy Oxides

• DOI: 10.1021/acsami.4c21521
• Publication Date: 2025-04-10T21:30:01Z
• Authors: Mao Sun; Yu Tang; Yueming Zhai; Jike Wang
• Keywords: Oxygen evolution; Joule–Thomson effect; Joule (programming language)

Uncontrolled high temperatures cause catalyst morphology collapse and phase transformation, hindering active site exposure. To address this issue, we extend Newton's law of cooling to achieve precise time control within seconds using a Joule heating device. This approach enables the synthesis CoFeNiMnCr high-entropy oxide (HEO) with large surface area abundant defect states. The resulting HEO demonstrates excellent performance, requiring only 219 mV overpotential at 10 mA cm-2 maintaining stability for 320 h 100 cm-2, ranking among most effective OER catalysts date. Notably, our findings indicate that has more significant influence on activity than time. In situ Raman spectroscopy confirms transformation spinel-type metal (oxy)hydroxide sites highlights synergistic effects multimetallic composition. work provides valuable insights into optimizing high-performance materials.