Carbonaceous photonic crystals prepared by high-temperature/hydrothermal carbonization as high-performance microwave absorbers

Carbonaceous photonic crystals (CPCs) were prepared from peacock feather fibers (PFF) via high-temperature carbonization (HTC) and hydrothermal carbonization (HC), and by comparing the optical reflection microphotographs, the CPCs-HTC and CPCs-HC still owned the structural coloration as the natural PFF. Raman results showed that the I-D/I-G value of CPCs-HTC was higher than the one of CPCs-HC, demonstrating more defects and higher graphitization degree of CPCs-HTC. Due to the presence of defects and the different degrees of graphitization, complex permittivity of CPCs can be controlled. The microwave absorption performance of 30 wt% CPCs-HTC was better than the CPCs-HC. The minimum reflection loss (RL) of CPCs-HTC was - 57.9 dB when the frequency was 7.3 GHz and the thickness was 2.5 mm. The frequency range, in which the RL values were less than - 10 dB, was 6.4-8.5 GHz. Compared with other biomass-derived materials, the CPCs-HTC shows several advantages, such as the specific photonic structure, simple preparation process and excellent microwave absorption performances. Thus, CPCs-HTC has the potential to be a lightweight microwave absorption material.