Zhou Qixing, Zhang Sike, Zhou Guangyao, Pang Huan, Zhang Mingyi, Xu Lin, Sun Kang, Tang Yawen, Huang Kai
School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, P. R. China.
Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
Small. 2023 Jul;19(28):e2301324. doi: 10.1002/smll.202301324. Epub 2023 Apr 2.
The design of economical, efficient, and robust bifunctional oxygen electrocatalysts is greatly imperative for the large-scale commercialization of rechargeable Zn-air battery (ZAB) technology. Herein, the neoteric design of an advanced bifunctional electrocatalyst composed of CoN/Co O heterojunction hollow nanoparticles in situ encapsulated in porous N-doped carbon nanowires (denoted as CoN/Co O HNPs@NCNWs hereafter) is reported. The simultaneous implementation of interfacial engineering, nanoscale hollowing design, and carbon-support hybridization renders the synthesized CoN/Co O HNPs@NCNWs with modified electronic structure, improved electric conductivity, enriched active sites, and shortened electron/reactant transport pathways. Density functional theory computations further demonstrate that the construction of a CoN/Co O heterojunction can optimize the reaction pathways and reduce the overall reaction barriers. Thanks to the composition and architectural superiorities, the CoN/Co O HNPs@NCNWs exhibit distinguished oxygen reduction reaction and oxygen evolution reaction performance with a low reversible overpotential of 0.725 V and outstanding stability in KOH medium. More encouragingly, the homemade rechargeable liquid and flexible all-solid-state ZABs utilizing CoN/Co O HNPs@NCNWs as the air-cathode deliver higher peak power densities, larger specific capacities, and robust cycling stability, exceeding the commercial Pt/C + RuO benchmark counterparts. The concept of heterostructure-induced electronic modification herein may shed light on the rational design of advanced electrocatalysts for sustainable energy applications.
设计经济、高效且稳健的双功能氧电催化剂对于可充电锌空气电池（ZAB）技术的大规模商业化至关重要。在此，报道了一种新型的双功能电催化剂的设计，该催化剂由原位封装在多孔氮掺杂碳纳米线中的CoN/CoO异质结空心纳米颗粒组成（以下简称CoN/CoO HNPs@NCNWs）。界面工程、纳米级中空设计和碳载体杂化的同时实施，使得合成的CoN/CoO HNPs@NCNWs具有改性的电子结构、提高的电导率、丰富的活性位点以及缩短的电子/反应物传输路径。密度泛函理论计算进一步表明，CoN/CoO异质结的构建可以优化反应路径并降低整体反应势垒。得益于其组成和结构优势，CoN/CoO HNPs@NCNWs在KOH介质中表现出卓越的氧还原反应和析氧反应性能，可逆过电位低至0.725 V，且具有出色的稳定性。更令人鼓舞的是，以CoN/CoO HNPs@NCNWs作为空气阴极的自制可充电液体和柔性全固态ZABs具有更高的峰值功率密度、更大的比容量和稳健的循环稳定性，超过了商业Pt/C + RuO基准对应物。本文中异质结构诱导电子改性的概念可能为可持续能源应用中先进电催化剂的合理设计提供启示。
