Xu Xueqing, Ran Feitian, Fan Zhimin, Cheng Zhongjun, Lv Tong, Shao Lu, Liu Yuyan
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, P.R. China.
Aerospace Institute of Advanced Material & Processing Technology, Beijing 100074, P.R. China.
ACS Appl Mater Interfaces. 2020 Apr 15;12(15):17870-17880. doi: 10.1021/acsami.0c01572. Epub 2020 Apr 1.
Metal-organic frameworks (MOFs) featuring high porosity and tunable structure make them become promising candidates to fabricate carbon-based microwave absorption (MA) materials to meet the requirements of electronic reliability and defense security. However, it is challenging to rationally design a well-organized micro-nanostructure to simultaneously achieve strong and wideband MA performance. Herein, a three-dimensional (3D) hierarchical nanoarchitecture (CoNi@NC/rGO-600) comprising pomegranate-like CoNi@NC nanoclusters and ultrasmall CoNi-decorated graphene has been successfully fabricated to broaden the absorption bandwidth and enhance the absorption intensity. The results confirm that the bimetallic MOF CoNi-BTC-derived pomegranate-like CoNi@NC nanoclusters with porous carbon shell as "peel" and sub-5 nm CoNi nanoparticles as "seeds" favor multiple polarization, magnetic loss, and impedance matching. Moreover, the interconnected 3D CoNi-doped graphene acts not only as a bridge to connect pomegranate-like CoNi@NC nanoclusters but also as a conductive network to supply multiple electron transportation paths. Consequently, the optimized CoNi@NC/rGO-600 exhibits extraordinary MA performance in terms of wide bandwidth (6.7 GHz) and strong absorption (-68.0 dB). As an effective strategy, this work provides a new insight into fabricating hierarchical composite structures for advancing MA performances and other applications.
具有高孔隙率和可调节结构的金属有机框架（MOF）使其成为制造碳基微波吸收（MA）材料的有前途的候选者，以满足电子可靠性和国防安全的要求。然而，合理设计一个组织良好的微纳米结构以同时实现强而宽带的MA性能具有挑战性。在此，一种由石榴状CoNi@NC纳米团簇和超小CoNi修饰的石墨烯组成的三维（3D）分级纳米结构（CoNi@NC/rGO-600）已成功制备，以拓宽吸收带宽并增强吸收强度。结果证实，具有多孔碳壳作为“果皮”和亚5nm CoNi纳米颗粒作为“种子”的双金属MOF CoNi-BTC衍生的石榴状CoNi@NC纳米团簇有利于多极化、磁损耗和阻抗匹配。此外，相互连接的3D CoNi掺杂石墨烯不仅作为连接石榴状CoNi@NC纳米团簇的桥梁，而且作为提供多个电子传输路径的导电网络。因此，优化后的CoNi@NC/rGO-600在宽带宽（6.7GHz）和强吸收（-68.0dB）方面表现出非凡的MA性能。作为一种有效策略，这项工作为制造分级复合结构以提高MA性能和其他应用提供了新的见解。
