High yield production of lightweight porous carbon from petroleum coke towards efficient electromagnetic waves absorption in the multi-frequency range

In order to achieve better protection for electronic devices operating at different frequencies, it is necessary to investigate frequency-insensitive electromagnetic waves absorbing materials, which are able to achieve high absorption at multiple frequencies by only changing the thickness. In this paper, three-dimensional (3D) porous carbon materials (3DPC) were successfully fabricated via a facile heat treatment strategy by using petroleum coke and NaHCO₃ as carbon resource and salt template, respectively. The 3DPC material owns a favorable degree of graphitization and 3D porous structure, exhibiting an efficient absorption over −50 dB at multiple frequencies. Furthermore, a series of carbon materials with different morphologies were prepared via different salt templates. The results show that the well-built 3D porous configuration indeed acts a vital role in achieving efficient absorption property in multiple wavebands. This work provides a pioneering idea for development of frequency-insensitive electromagnetic waves absorbing materials and the high value-added utilization of petroleum coke.