Kim Hyun-Chul, Huh Seong
Department of Chemistry and Protein Research Center for Bio-Industry, Hankuk University of Foreign Studies, Yongin 17035, Korea.
Materials (Basel). 2020 Sep 22;13(18):4215. doi: 10.3390/ma13184215.
Numerously different porous carbons have been prepared and used in a wide range of practical applications. Porous carbons are also ideal electrode materials for efficient energy storage devices due to their large surface areas, capacious pore spaces, and superior chemical stability compared to other porous materials. Not only the electrical double-layer capacitance (EDLC)-based charge storage but also the pseudocapacitance driven by various dopants in the carbon matrix plays a significant role in enhancing the electrochemical supercapacitive performance of porous carbons. Since the electrochemical capacitive activities are primarily based on EDLC and further enhanced by pseudocapacitance, high-surface carbons are desirable for these applications. The porosity of carbons plays a crucial role in enhancing the performance as well. We have recently witnessed that metal-organic frameworks (MOFs) could be very effective self-sacrificing templates, or precursors, for new high-surface carbons for supercapacitors, or ultracapacitors. Many MOFs can be self-sacrificing precursors for carbonaceous porous materials in a simple yet effective direct carbonization to produce porous carbons. The constituent metal ions can be either completely removed during the carbonization or transformed into valuable redox-active centers for additional faradaic reactions to enhance the electrochemical performance of carbon electrodes. Some heteroatoms of the bridging ligands and solvate molecules can be easily incorporated into carbon matrices to generate heteroatom-doped carbons with pseudocapacitive behavior and good surface wettability. We categorized these MOF-derived porous carbons into three main types: (i) pure and heteroatom-doped carbons, (ii) metallic nanoparticle-containing carbons, and (iii) carbon-based composites with other carbon-based materials or redox-active metal species. Based on these cases summarized in this review, new MOF-derived porous carbons with much enhanced capacitive performance and stability will be envisioned.
人们已经制备了多种不同的多孔碳，并将其应用于广泛的实际领域。多孔碳也是高效储能装置的理想电极材料，因为与其他多孔材料相比，它们具有较大的表面积、宽敞的孔隙空间和优异的化学稳定性。不仅基于双电层电容（EDLC）的电荷存储，而且碳基质中各种掺杂剂驱动的赝电容在增强多孔碳的电化学超级电容性能方面都起着重要作用。由于电化学电容活性主要基于EDLC，并通过赝电容进一步增强，因此高表面积碳适用于这些应用。碳的孔隙率在提高性能方面也起着关键作用。我们最近发现，金属有机框架（MOF）对于用于超级电容器或超电容器的新型高表面积碳而言，可能是非常有效的自牺牲模板或前驱体。许多MOF可以通过简单而有效的直接碳化成为碳质多孔材料的自牺牲前驱体，以生产多孔碳。在碳化过程中，组成金属离子可以完全去除，也可以转化为有价值的氧化还原活性中心，用于额外的法拉第反应，以增强碳电极的电化学性能。桥连配体和溶剂化分子的一些杂原子可以很容易地掺入碳基质中，以生成具有赝电容行为和良好表面润湿性的杂原子掺杂碳。我们将这些源自MOF的多孔碳分为三种主要类型：（i）纯碳和杂原子掺杂碳，（ii）含金属纳米颗粒的碳，以及（iii）与其他碳基材料或氧化还原活性金属物种的碳基复合材料。基于本综述中总结的这些案例，可以设想具有大大增强的电容性能和稳定性的新型源自MOF的多孔碳。
