Xie Yuhua, Feng Yumei, Zhu Shiao, Yu Yingjie, Bao Haifeng, Liu Qingting, Luo Fang, Yang Zehui
State Key Laboratory of New Textile Materials & Advanced Processing Technology, College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
Faculty of Materials Science and Chemistry, China University of Geosciences Wuhan, 388 Lumo RD, Wuhan, 430074, China.
Adv Mater. 2025 Feb;37(5):e2414801. doi: 10.1002/adma.202414801. Epub 2024 Dec 4.
High-performance bifunctional electrocatalyst for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is the keystone for the industrialization of rechargeable zinc-air battery (ZAB). In this work, the modulation in the spin state of Fe single atom on nitrogen doped carbon (Fe-NC) is devised by CoO (CoO@Fe-NC), and a mediate spin state is recorded. Besides, the d band center of Fe is downshifted associated with the increment in e filling revealing the weakened interaction with OH moiety, resulting in a boosted ORR performance. The ORR kinetic current density of CoO@Fe-NC is 2.0- and 5.6 times higher than Fe-NC and commercial Pt/C, respectively. Moreover, high spin state is found for Co in CoO@Fe-NC contributing to the accelerated surface reconstruction of CoO witnessed by operando Raman and electrochemical impedance spectroscopies. A robust OER activity with overpotential of 352 mV at 50 mA cm is achieved, decreased by 18 and 60 mV by comparison with CoO@NC and IrO. The operando Raman reveals a balanced adsorption of OH species and its deprotonation leading to robust stability. The ZAB performance of CoO@Fe-NC is 193.2 mW cm and maintains for 200 h. Furthermore, the all-solid-state ZAB shows a promising battery performance of 163.1 mW cm.
用于析氧反应（OER）和氧还原反应（ORR）的高性能双功能电催化剂是可充电锌空气电池（ZAB）工业化的关键。在这项工作中，通过CoO（CoO@Fe-NC）设计了氮掺杂碳上铁单原子（Fe-NC）自旋态的调制，并记录到了中间自旋态。此外，Fe的d带中心随着电子填充的增加而向下移动，这表明与OH部分的相互作用减弱，从而提高了ORR性能。CoO@Fe-NC的ORR动力学电流密度分别比Fe-NC和商业Pt/C高2.0倍和5.6倍。此外，通过原位拉曼光谱和电化学阻抗谱证实，CoO@Fe-NC中Co的高自旋态有助于加速CoO的表面重构。在50 mA cm时实现了352 mV过电位的稳健OER活性，与CoO@NC和IrO相比分别降低了18 mV和60 mV。原位拉曼光谱显示OH物种的平衡吸附及其去质子化导致了稳健的稳定性。CoO@Fe-NC的ZAB性能为193.2 mW cm，并保持200 h。此外，全固态ZAB显示出163.1 mW cm的良好电池性能。
