Non-noble metal-based amorphous high-entropy oxides as efficient and reliable electrocatalysts for oxygen evolution reaction

Exploring high-performance and cost-effective electrocatalysts that are applicable in oxygen evolution reaction(OER)is crucial for water splitting and energy storage.In this work,a facile and scalable chemical reduction strategy is developed to synthesize FeCoNiPB non-noble metal-based amorphous high-entropy oxides for the OER in alkaline media.The FeCoNiPB oxides exhibit overpotentials of 235 and 306 mV at current densities of 10 and 100 mA/cm^(2),respectively,as well as a small Tafel slope of 53 mV/dec in 1.0 M KOH solution,outperforming the performance of FeCoPB,FeNiPB,and CoNiPB oxides and the commercial RuO_(2),while maintaining excellent stability with negligible overpotential amplification over 40 h.The superior OER electrocatalytic efficiency and stability of the FeCoNiPB catalyst is primarily attributed to its unique amorphous high-entropy nanostructure,synergistic effect of the multiple components,and in situ-formed amorphous sheets with a thin(FeCoNi)OOH crystalline layer on the edge during long-term OER.This work provides new insights to design and prepare low-cost,highly efficient,and durable OER electrocatalysts.