Research progress on high entropy alloys and high entropy derivatives as OER catalysts

High entropy alloys are made by mixing five or more elements at equal or nearly equal atomic ratios. They have demonstrated significant interests in many fields. However, due to the short time of their development, many HEAs fields have not been studied in sufficient depth. Surprisingly, HEAs have achieved significant results in the field of functional materials, especially in serving as an oxygen evolution reaction catalyst for electrochemical water cracking. The complex surface environment of HEAs and the multi-metal synergistic effect give HEAs excellent OER catalytic properties. In addition, some high entropy derivatives have also been demonstrated as excellent OER catalysts. This review describes the current research status and great potential of HEAs and high entropy derivatives as OER catalysts. The development of high entropy alloys and two OER mechanisms are summarized. This includes a systematic analysis of how the various parameters influence the catalysis performance including the surface morphology, synthesis strategies and OER properties of HEAs as well as high-entropy derivatives. HEAs with the same synthesis strategy are summarized, as well as the application of DFT calculations to HEAs. This article provides some insights and possible solutions regarding the construction of reliable HEA as OER catalysis. Finally, insights are offered on the future directions and prospects in the field of HEA catalysts.