Sun Yinqing, Guan Yi, Wu Xiaochao, Li Wanqing, Li Yongliang, Sun Lingna, Mi Hongwei, Zhang Qianling, He Chuanxin, Ren Xiangzhong
College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
Nanoscale. 2021 Feb 11;13(5):3227-3236. doi: 10.1039/d0nr07892a.
The rational design and construction of the efficient and robust non-noble metal bifunctional oxygen electrocatalysts is of critical significance due to the attention given to reversible metal-air batteries. In this paper, we report novel two-dimensional "senbei"-like Co9S8/CeO2/Co-NC nitrogen-doped carbon nanosheets (Co9S8/CeO2/Co-NC) derived from a unique 2D Co/Ce bimetallic ZIF. The phase transition from 3D spherical Co-ZIF to 2D Co/Ce-ZIF was achieved through the introduction of Ce ions. Profiting from the successful construction of the unique Co9S8/CeO2 heterostructure and the synergetic effect of two components, the as-prepared Co9S8/CeO2/Co-NC exhibited excellent electro-performance in both the oxygen evolution reaction (Ej=10 = 1.60 V) and oxygen reduction reaction (E1/2 = 0.875 V). Furthermore, when used as a bifunctional air electrode for Zn-air batteries, Co9S8/CeO2/Co-NC reached a high peak power density of ≈164.24 mW cm-2 at a high current density of ≈351 mA cm-2 and displayed an outstanding cycling stability of more than 668 h at 5 mA cm-2. This research provides new guidelines for preparing hybrid materials from cobalt-based sulfide species and CeO2 for electrocatalysis and energy storage or other fields.
由于对可逆金属空气电池的关注，高效且耐用的非贵金属双功能氧电催化剂的合理设计与构建具有至关重要的意义。在本文中，我们报道了一种新型的二维“仙贝”状Co9S8/CeO2/Co-NC氮掺杂碳纳米片（Co9S8/CeO2/Co-NC），它源自独特的二维Co/Ce双金属沸石咪唑酯骨架结构材料（ZIF）。通过引入Ce离子实现了从三维球形Co-ZIF到二维Co/Ce-ZIF的相变。得益于独特的Co9S8/CeO2异质结构的成功构建以及两种组分的协同效应，所制备的Co9S8/CeO2/Co-NC在析氧反应（Ej=10 = 1.60 V）和氧还原反应（E1/2 = 0.875 V）中均表现出优异的电性能。此外，当用作锌空气电池的双功能空气电极时，Co9S8/CeO2/Co-NC在≈351 mA cm-2的高电流密度下达到了≈164.24 mW cm-2的高峰值功率密度，并在5 mA cm-2下显示出超过668 h的出色循环稳定性。本研究为从钴基硫化物和CeO2制备用于电催化、能量存储或其他领域的混合材料提供了新的指导方针。
