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Abstract Nanoparticles supported on carbonaceous substrates are promising electrocatalysts. However, achieving good stability for the electrocatalysts during long‐term operations while maintaining high activity remains a grand challenge. Herein, a highly stable and active electrocatalyst featuring high‐entropy oxide (HEO) nanoparticles uniformly dispersed on commercial carbon black is reported, which is synthesized via rapid high‐temperature heating (≈1 s, 1400 K). Notably, the HEO nanoparticles with a record‐high entropy are composed of ten metal elements (i.e., Hf, Zr, La, V, Ce, Ti, Nd, Gd, Y, and Pd). The rapid high‐temperature synthesis can tailor structural stability and avoid nanoparticle detachment or agglomeration. Meanwhile, the high‐entropy design can enhance chemical stability to prevent elemental segregation. Using oxygen reduction reaction as a model, the 10‐element HEO exhibits good activity and greatly enhances stability (i.e., 92% and 86% retention after 12 and 100 h, respectively) compared to the commercial Pd/C electrocatalyst (i.e., 76% retention after 12 h). This superior performance is attributed to the high‐entropy compositional design and synthetic approach, which offers an entropy stabilization effect and strong interfacial bonding between the nanoparticles and carbon substrate. The approach promises a viable route toward synthesizing carbon‐supported high‐entropy electrocatalysts with good stability and high activity for various applications.
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Electrospun single-phase spinel magnetic high entropy oxide nanoparticles via low-temperature ambient annealing
High entropy oxide nanoparticles (HEO NPs) with multiple component elements possess improved stability and multiple uses for functional applications, including catalysis, data memory, and energy storage. However, the synthesis of homogenous HEO NPs containing five or more immiscible elements with a single-phase structure is still a great challenge due to the strict synthetic conditions. In particular, several synthesis methods of HEO NPs require extremely high temperatures. In this study, we demonstrate a low cost, facile, and effective method to synthesize three- to eight-element HEO nanoparticles by a combination of electrospinning and low-temperature ambient annealing. HEO NPs were generated by annealing nanofibers at 330 °C for 30 minutes under air conditions. The average size of the HEO nanoparticles was ∼30 nm and homogenous element distribution was obtained from post-electrospinning thermal decomposition. The synthesized HEO NPs exhibited magnetic properties with the highest saturation magnetization at 9.588 emu g −1 and the highest coercivity at 147.175 Oe for HEO NPs with four magnetic elements while integrating more nonmagnetic elements will suppress the magnetic response. This electrospun and low-temperature annealing method provides an easy and flexible design for nanoparticle composition and economic processing pathway, which offers a cost- and energy-effective, and high throughput entropy nanoparticle synthesis on a large scale.
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- PAR ID:
- 10424011
- Date Published:
- Journal Name:
- Nanoscale Advances
- Volume:
- 5
- Issue:
- 11
- ISSN:
- 2516-0230
- Page Range / eLocation ID:
- 3075 to 3083
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D3NA00090G
