Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, People's Republic of China.
Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, People's Republic of China.
J Colloid Interface Sci. 2023 Jul 15;642:1-12. doi: 10.1016/j.jcis.2023.03.133. Epub 2023 Mar 24.
The realization of durable and efficient oxygen evolution reactions (OER) at large current densities and low overpotentials is of significant importance but remains a great challenge. In this study, a CoFe/CoFeS@NS-CNTs/CC (CF/CFS@NS-CNTs/CC) heterogeneous structure was fabricated by isolating CoFe/CoFeS (CF/CFS) particles locked in nitrogen/sulfur codoped carbon nanotubes (NS-CNTs). Appreciable oxygen evolution reaction activity and durability was achieved with an ultralow overpotential of 110 mV at 10 mA•cm. The operation was stable for 300 h at a current density of 500 mA•cm. The structure was then assembled into a zinc-air battery (ZAB), which delivered a high power density of 194 mW•cm, a specific capacity of 837.3 mAh•g, and stable operation for 788 h without obvious voltage attenuation and altered morphology. The electronic interactions were studied by X-ray photoelectron spectroscopy (XPS), which revealed that both the bimetal components and the synergistic effect at the interface stimulated the transfer of Co and Fe sites to higher chemical valence states. Theoretical calculations indicated that the synergistic effect of the bimetal components, build-in interfacial potential, and surface chemical reconstruction adjusted the Fermi level to optimize the thermodynamic formation of O* to OOH*, thus enhancing the intrinsic activity.
在大电流密度和低过电势下实现持久且高效的氧析出反应（OER）具有重要意义，但仍然是一个巨大的挑战。在这项研究中，通过将 CoFe/CoFeS（CF/CFS）颗粒锁定在氮/硫共掺杂碳纳米管（NS-CNTs）中，制备了 CoFe/CoFeS@NS-CNTs/CC（CF/CFS@NS-CNTs/CC）异质结构。该结构具有超低的过电势 110 mV，在 10 mA•cm 时可实现优异的氧析出反应活性和耐久性。在 500 mA•cm 的电流密度下，该结构稳定运行 300 h。然后，该结构被组装成锌-空气电池（ZAB），其功率密度为 194 mW•cm，比容量为 837.3 mAh•g，稳定运行 788 h，电压衰减不明显，形态未发生改变。通过 X 射线光电子能谱（XPS）研究了电子相互作用，结果表明，双金属成分和界面协同效应都促进了 Co 和 Fe 位向更高化学价态的转移。理论计算表明，双金属成分的协同效应、内置界面势和表面化学重构调整了费米能级，从而优化了 O到 OOH的热力学形成，提高了本征活性。
