High entropy alloy nanoparticles encapsulated in graphitised hollow carbon tubes for oxygen reduction electrocatalysis

• Published in: Dalton transactions : an international journal of inorganic chemistry 2023-03, Vol.52 (13), p.4142-4151
• Main Authors: Yao, Yuechao, Li, Zhangjian, Dou, Yibo, Jiang, Tao, Zou, Jizhao, Lim, Sung Yul, Norby, Poul, Stamate, Eugen, Jensen, Jens Oluf, Zhang, Wenjing
• Format: Article
• Language: English
• Subjects: Alloys; Carbon; Catalysts; Chemical reduction; Electrocatalysis; Electrocatalysts; Encapsulation; Energy storage; High entropy alloys; Metal air batteries; Nanoalloys; Nanoparticles; Oxygen reduction reactions; Transition metals; Tubes; Zinc-oxygen batteries
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d2dt03637a

High entropy alloys (HEAs) with a tunable alloy composition and fascinating synergetic effects between various metals have attracted significant attention in the field of electrocatalysis, but their potential is limited by inefficient and unscalable fabrication methodologies. This work proposes a novel solid-state thermal reaction method to synthesise HEA nanoparticles encapsulated in an N-doped graphitised hollow carbon tube. This facile method is simple and efficient and involves no use of organic solvents during the fabrication process. The synthesized HEA nanoparticles are confined by the graphitised hollow carbon tube, which is possibly beneficial for preventing the aggregation of alloy particles during the oxygen reduction reaction (ORR). In a 0.1 M KOH solution, the HEA catalyst FeCoNiMnCu-1000(1 : 1) exhibits an onset and half-wave potential of 0.92 V and 0.78 V ( vs. RHE), respectively. We assembled a Zn-Air battery with FeCoNiMnCu-1000 as a catalyst for the air electrode, and a power density of 81 mW cm −2 and a long-term durability of >200 h were achieved, which is comparable to the performance of the state-of-the-art catalyst Pt/C-RuO 2 . This work herein offers a scalable and green method for synthesising multinary transition metal-based HEAs and highlights the potential of HEA nanoparticles as electrocatalysts for energy storage and conversion. High entropy alloys (HEAs) are encapsulated in graphitized hollow carbon tubes to confine the growth of alloy particles during the formation process. Zinc-air batteries with HEAs as air electrodes exhibit long-lasting durability and high efficiency.