Cheng Chen, Chongqing Yang, Xiaobin Fu, Yilong Yang, Senhe Huang, Junbo Hou, Min Yang, Yuezeng Su, Xiaodong Zhuang
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引用次数: 0
Abstract
The specific performance of two-dimensional conductive metal–organic frameworks (MOFs) in energy storage devices is significantly constrained by the presence of bulky redox-active centers and densely packed interlayers. Herein, we report two semi-conductive MOFs, Fe-MOF and Cr-MOF, using a small aromatic linker, pyrazine (pyz). Both MOFs demonstrated exceptional capacitive properties in an ionic electrolyte. Despite having similar layered AB-stacking geometries and non-porous structures, the single-crystalline Fe-MOF demonstrated weaker redox interactions between Fe2+ and pyz nodes, resulting in typical semiconducting properties with a bandgap of ∼1.07 eV. In contrast, the Cr-MOF exhibited a high conductivity, reaching 9.0 mS cm−1 at 350 K. Remarkably, the Fe-MOF electrode delivered a specific capacitance of 436.7 F g−1 at 0.5 A g−1, almost three times higher than that of the Cr-MOF (123.5 F g−1), despite its larger bandgap. Moreover, a high energy density of 98.2 W h kg−1 and excellent cycling stability (retaining 95.3% after 10 000 cycles) have been achieved in the Fe-MOF electrode. In situ experimental analysis together with theoretical calculations revealed that the superior charge storage capability of the Fe-MOF originated from the participation of both cations and anions in the diffusion-controlled charge storage, even with a non-porous structure. This study enhances our understanding of energy storage mechanisms in non-porous conductive MOFs and provides valuable insights for the development of advanced MOF materials for future energy storage applications.
期刊介绍:
The Journal of Materials Chemistry A, B & C covers a wide range of high-quality studies in the field of materials chemistry, with each section focusing on specific applications of the materials studied. Journal of Materials Chemistry A emphasizes applications in energy and sustainability, including topics such as artificial photosynthesis, batteries, and fuel cells. Journal of Materials Chemistry B focuses on applications in biology and medicine, while Journal of Materials Chemistry C covers applications in optical, magnetic, and electronic devices. Example topic areas within the scope of Journal of Materials Chemistry A include catalysis, green/sustainable materials, sensors, and water treatment, among others.