Three factors make bulk high-entropy alloys as effective electrocatalysts for oxygen evolution

Autor: Tao Zhang, Hui-Feng Zhao, Ke-Yan Wang, Zhen-Jie Chen, Li Li, Jing Peng, Xu Peng, Yong-Jiang Huang, Hai-Bin Yu
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Materials Futures, Vol 2, Iss 4, p 045101 (2023)
Druh dokumentu: article
ISSN: 2752-5724
DOI: 10.1088/2752-5724/aceef3
Popis: Even in their bulk forms, complex alloys like high-entropy alloys (HEAs) exhibit favorable activity and stability as electrocatalysts for the oxygen evolution reaction (OER). However, the underlying reasons are not yet fully understood. In a family of Mo-doped CrFeCoNi-based HEAs, we have identified three crucial factors that govern their performance: (i) homogeneous solid solution phase of HEAs helps to maintain high-valence states of metals; (ii) surface reconstruction results in a hybrid material comprising amorphous domains and percolated crystalline structures; (iii) diversity of active intermediate species (M–O, M–OOH, and, notably, the abundance of superoxide μ –OO), which display stronger adsorption capacity on the reconstructed surface. These results are revealing due to their resemblance to findings in other families of electrocatalysts for OER, as well as their unique features specific to HEAs. In line with these factors, a CrFeCoNiMo _0.2 bulk integrated electrode displays a low overpotential of 215 mV, rapid kinetics, and long-term stability of over 90 d. Bulk HEAs hold great potential for industrial applications.
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