Ultrasound-Assisted Synthesis of High-Entropy Materials for Enhanced Oxygen Evolution Electrocatalysis

Abstract

High-entropy materials (HEMs) play a significant role in the electrocatalytic oxygen evolution reaction (OER) due to their unique properties. However, there are still challenges in the preparation of HEMs for OER catalysts. In this study, the FeCoNiMnCr catalyst is synthesized for the first time using the ultrasonic hydrothermal-sintering technique and exhibits excellent performance for OER electrocatalysis. There is an optimal ultrasonic hydrothermal time and power for achieving the best OER performance. The results demonstrate that the performance of FeCoNiMnCr catalysts prepared through ultrasonic hydrothermal sintering (US-FeCoNiMnCr) is significantly improved compared with the traditional hydrothermal-sintering method. The US-FeCoNiMnCr catalyst exhibits an overpotential of 228 mV at the current density of 10 mA cm−2 and a Tafel slope as low as 45.39 mV dec−1 in an alkaline medium. Moreover, the US-FeCoNiMnCr catalyst demonstrates remarkable stability in electrocatalytic OER with a minimal potential increase observed even after 48 h. This work not only provides valuable insights into high-entropy material synthesis, but also presents a powerful electrocatalyst for water electrolysis.

Keywords

• high-entropy materials
• ultrasonic hydrothermal-sintering method
• oxygen evolution reaction
• in situ Raman