Heterostructured CoFe/Co nanoalloys encapsulated in N-doped carbon as bifunctional oxygen-electrode catalysts for Zn-air batteries

IF 2.9 3区化学 Q3 CHEMISTRY, PHYSICAL

Physical Chemistry Chemical Physics Pub Date : 2025-06-20 DOI:10.1039/d5cp00941c

Xiao-Wei Song, Min Lin, Hui Zhao, Ruoxuan Sun, Ye-Bin Guan

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Abstract

Developing bifunctional oxygen electrocatalysts based on non-precious elements for the air electrodes of rechargeable Zn-air batteries (ZABs) remains a significant challenge. Herein, by adjusting the Co precursor content, we synthesized a bifunctional electrocatalyst (CoFe@NC-5) comprising CoFe/Co nanoalloys (~16 nm) encapsulated in N-doped carbon. The CoFe@NC-5 catalyst features the highest metal loading (37.24 wt% Co+Fe), uniform nanoalloy distribution, a unique encapsulated structure, and well-defined heterojunction interfaces between CoFe and Co phases. These characteristics endow CoFe@NC-5 with excellent bifunctional oxygen electrode activity, as evidenced by a low potential gap (ΔE) of 0.757 V between the half-wave potential for the oxygen reduction reaction (ORR, 0.84 V) and the potential for the oxygen evolution reaction (OER, 1.597 V) at 10 mA cm⁻². Density functional theory (DFT) calculations further reveal that the heterojunction interfaces in the CoFe/Co heterostructure of the CoFe@NC-5 catalyst significantly enhance interfacial electron accumulation and shift the d-band center closer to the Fermi level, thereby boosting its ORR and OER activities. Furthermore, a rechargeable ZAB assembled with CoFe@NC-5 as the air electrode exhibits a high power density of 363.7 mW cm⁻², a specific capacity of 785.8 mAh g_Zn⁻¹ at 50 mA cm⁻², and stable charge-discharge cycling for 330 hours.

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氮掺杂碳包封异质结构CoFe/Co纳米合金作为锌空气电池双功能氧电极催化剂

开发基于非贵金属元素的双功能氧电催化剂用于可充电锌空气电池（ZABs）的空气电极仍然是一个重大挑战。通过调整Co前驱体的含量，我们合成了一种双功能电催化剂（CoFe@NC-5），该催化剂由n掺杂碳包裹的CoFe/Co纳米合金（~16 nm）组成。CoFe@NC-5催化剂具有最高的金属负载（37.24 wt% Co+Fe），均匀的纳米合金分布，独特的封装结构，以及CoFe和Co相之间明确的异质结界面。这些特性使得CoFe@NC-5具有优异的双功能氧电极活性，在10 mA cm−2时，氧还原反应的半波电位（ORR, 0.84 V）和析氧反应的半波电位（OER, 1.597 V）之间的电位间隙（ΔE）很小，为0.757 V。密度泛函理论（DFT）计算进一步表明，CoFe@NC-5催化剂的CoFe/Co异质结构中的异质结界面显著增强了界面电子积累，使d带中心向费米能级移动，从而提高了其ORR和OER活性。此外，以CoFe@NC-5为空气电极组装的可充电ZAB具有363.7 mW cm - 2的高功率密度，50ma cm - 2时的gZn - 1比容量为785.8 mAh，可稳定充放电循环330小时。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Physical Chemistry Chemical Physics 化学-物理：原子、分子和化学物理

CiteScore

5.50

自引率

9.10%

发文量

2675

审稿时长

2.0 months

期刊介绍： Physical Chemistry Chemical Physics (PCCP) is an international journal co-owned by 19 physical chemistry and physics societies from around the world. This journal publishes original, cutting-edge research in physical chemistry, chemical physics and biophysical chemistry. To be suitable for publication in PCCP, articles must include significant innovation and/or insight into physical chemistry; this is the most important criterion that reviewers and Editors will judge against when evaluating submissions. The journal has a broad scope and welcomes contributions spanning experiment, theory, computation and data science. Topical coverage includes spectroscopy, dynamics, kinetics, statistical mechanics, thermodynamics, electrochemistry, catalysis, surface science, quantum mechanics, quantum computing and machine learning. Interdisciplinary research areas such as polymers and soft matter, materials, nanoscience, energy, surfaces/interfaces, and biophysical chemistry are welcomed if they demonstrate significant innovation and/or insight into physical chemistry. Joined experimental/theoretical studies are particularly appreciated when complementary and based on up-to-date approaches.