Pt-Based High-Entropy Alloy Nanoparticles as Bifunctional Electrocatalysts for Hydrogen and Oxygen Evolution

Pt-based high-entropy alloys (HEA) enable high-performance electrocatalysts with a low Pt content. However, the current synthesis methods of HEAs suffer from complex processes, such as high temperatures or special manufacturing processes. In this work, a bottom-up shear-assisted liquid metal surface reduction strategy is introduced for the synthesis of sub-2 nm ultrasmall Pt-based HEA nanoparticles (NPs) at room temperature. To prove its utility, Co–Fe–Ni–Pt–Ta–vxc72 was found to exhibit excellent electrocatalytic activity and stability for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with overpotentials of 10.6 and 290 mV at 10 mA/cm2, respectively. At the same time, in both reactions, its stability can reach 20 h according to chronoamperometry. We expect that many nano-HEAs will be synthesized by our method and used in many other related applications in the future.