Wang Haiyan, Jiao Yakun, Wang Saijun, Ye Pengcheng, Ning Jiqiang, Zhong Yijun, Hu Yong
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, Jinhua, 321004, China.
Department of Optical Science and Engineering, Fudan University, Shanghai, 200438, China.
Small. 2021 Dec;17(49):e2103517. doi: 10.1002/smll.202103517. Epub 2021 Nov 1.
Rational engineering electrode structure to achieve an efficient triple-phase contact line is vital for applications such as in zinc-air batteries and water electrolysis. Herein, a facile "MOF-in situ-leaching and confined-growth-MOF" strategy is developed to construct a breathable trifunctional electrocatalyst based on N-doped graphitic carbon with Co nanoparticles spatially confined in an inherited honeycomb-like macroporous structure (denoted as Co@HMNC). The unique orderly arranged macroporous channels and the "ships in a bottle" confinement effect jointly expedite the triple transport, endowing the catalysts with fast reaction kinetics. As a result, the obtained Co@HMNC catalyst presents superb trifunctional performance with a positive half-wave potential (E ) of 0.90 V for oxygen reduction reaction (ORR), and low overpotentials of 318 and 51 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) at 10 mA cm , respectively. The Co@HMNC-based liquid Zn-air battery reaches a large specific capacity of 859 mA h g , a high-power density of 198 mW cm , and long-term stability for 375 h, suggesting its promise for actual applications.
合理设计电极结构以实现高效的三相接触线对于锌空气电池和水电解等应用至关重要。在此，开发了一种简便的“金属有机框架原位浸出和限域生长金属有机框架”策略，以构建一种基于氮掺杂石墨碳的透气三功能电催化剂，其中钴纳米颗粒空间限域在继承的蜂窝状大孔结构中（表示为Co@HMNC）。独特的有序排列大孔通道和“瓶中船”限域效应共同加速了三相传输，赋予催化剂快速的反应动力学。结果，所获得的Co@HMNC催化剂呈现出优异的三功能性能，氧还原反应（ORR）的正半波电位（E ）为0.90 V，在10 mA cm 时氧析出反应（OER）和析氢反应（HER）的过电位分别为318和51 mV。基于Co@HMNC的液态锌空气电池达到了859 mA h g 的大比容量、198 mW cm 的高功率密度以及375 h的长期稳定性，表明其在实际应用中的潜力。
