The Influence of Structural Compactness on the Microwave Absorption Performance of Metal−Organic Frameworks

Abstract With the development of electronic information technology and the increasingly severe international situation, the research and exploration of microwave absorbing materials (MAMs) have become more and more important. In order to explore the influence of structural compactness on the microwave absorption performance, this paper chooses flaky porous carbon derived from Ni-BDC-MOF as the MAMs, which studied the effects of interlayer spacing, pyrolysis temperature (500 °C, 600 °C, and 700 °C), and Ni alloys on the absorption performance of composite materials. Among the three composite materials, the Ni-BDC-500 and Ni-BDC-600 flaky-shaped porous carbon with smaller compactness exhibits excellent absorption performance. The value of RLmin reflects the loss intensity of the composite material at a single frequency, while the effective absorption bandwidth (EAB) can more intuitively demonstrate the EMWs absorption capability. The RLmin of Ni-BDC-500 and Ni-BDC-600 is −47.5 dB and −45 dB at 8.9 and 8.2 GHz with the thickness of 2.9 and 3.1 mm, respectively. And the EAB reached 5.1 GHz (11.4−16.5 GHz) and 7 GHz (8−15 GHz) at the thickness of 2.1 mm and 2.5 mm, respectively, which covers the X-band and Ku-band. The inference offers the technical way for developing outstanding performance MAMs with smaller compactness in practical engineering applications.