Enhancing the Water Oxidation Performance of Bulk Al1.2CrFe2Ni2 High Entropy Alloy Through Deep Cryogenic Treatment

Abstract

Owing to the distinctive physical and chemical characteristics of high entropy alloys (HEAs), their application in electrocatalysis has become a possibility. However, selecting appropriate means to improve the oxygen evolution reaction (OER) performance of bulk HEAs remains an urgent problem. In this study, we obtained an OER electrocatalyst containing FCC + BCC phase bulk HEAs with high catalytic activity through simple vacuum melting and deep cryogenic treatment. After 36 hours of treatment, the overpotential of Al1.2CrFe2Ni2 HER is 278.8 mV at 10 mA cm−2 for OER with a small Tafel slope of 53.45 mV dec−1. The catalyst can be continuously electrolyzed in 1 M KOH for over 50 hours. This work confirms the potential of deep cryogenic treatment to improve the performance of bulk HEA catalysts for OER.