Pseudopyrolysis of Metal-Organic Frameworks: A Synchronous Nucleation Mechanism to Synthesize Ultrafine Metal Compound Nanoparticles.
Pseudopyrolysis of Metal-Organic Frameworks: A Synchronous Nucleation Mechanism to Synthesize Ultrafine Metal Compound Nanoparticles.
复制标题
DOI：
10.1021/acs.nanolett.2c04244
复制
发表时间：
2023-01
期刊：
影响因子：
10.8
通讯作者：
Z. Cui;Qian Liu;Jinqi Zhu;Hao Wang;Mengluan Gao;Wenqing Wang;M. Yuen;Junqing Hu;Huifang Chen-Hu
中科院分区：
文献类型：
--
作者：
Z. Cui;Qian Liu;Jinqi Zhu;Hao Wang;Mengluan Gao;Wenqing Wang;M. Yuen;Junqing Hu;Huifang Chen-Hu
人们越来越多地研究金属有机框架（MOF）用于合成碳载金属基超细纳米颗粒（UNP）。然而，热解过程中碳骨架的崩溃和金属颗粒的聚集严重阻碍了其稳定性和应用。在这里，我们通过原位透射电子显微镜实验和异位结构分析揭示了 MOF 的同步成核假热解将 Fe/FeOx UNP 限制在完整的多孔碳纳米棒（IPCN）中。假热解机制通过适度的热动力学和丰富的氧缺陷，在 UNP 和碳之间产生强烈的物理和化学限制效应。此外，这种强约束非常有利于后续化学转化以获得不同的铁基UNP和优异的电化学性能。作为概念证明，IPCN 中制备的 FeSe UNP 显示出优异的锂存储性能，在 0.1 A g -1 下具有 815.1 mAh g-1 的超高且稳定的容量，在 5 A g-1 下具有 379.7 mAh g-1 的超高容量，循环 1000 次。
Metal-Organic frameworks (MOFs) are increasingly being investigated for the synthesis of carbon-supported metal-based ultrafine nanoparticles (UNPs). However, the collapse of the carbon framework and aggregation of metal particles in the pyrolysis process have severely hindered their stability and applications. Here, we report the synchronous nucleation pseudopyrolysis of MOFs to confine Fe/FeOx UNPs in intact porous carbon nanorods (IPCNs), revealed by in situ transmission electron microscopy experiments and ex situ structure analysis. The pseudopyrolysis mechanism enables strong physical and chemical confinement effects between UNPs and carbon by moderate thermal kinetics and abundant oxygen defects. Further, this strong confinement is greatly beneficial for subsequent chemical transformations to obtain different Fe-based UNPs and excellent electrochemical performance. As a proof of concept, the as-prepared FeSe UNPs in IPCNs show superior lithium storage performance with an ultrahigh and stable capacity of 815.1 mAh g-1 at 0.1 A g -1 and 379.7 mAh g-1 at 5 A g-1 for 1000 cycles.