Facile fabrication of iron-sulfur co-doped porous carbon based on the hyper-crosslinking technique for efficient electromagnetic wave absorption

Abstract

Applications of porous carbon materials for electromagnetic wave absorption have been extensively documented. Nonetheless, the limited electromagnetic loss mechanisms impede the attainment of superior absorption performance. In this study, an iron-sulfur co-doped hyper-crosslinked polymer precursor was synthesized via a straightforward one-pot reaction. Subsequent carbonization yielded an iron-sulfur co-doped porous carbon wave absorber. The material exhibited a minimum reflection loss of −55.9 dB at a thickness of 2.5 mm, with a maximum bandwidth of 5.84 GHz at 2.0 mm. Conductivity loss was quantified through nonlinear fitting based on electromagnetic parameter analysis in conjunction with Cole-Cole semicircle analysis. The findings indicate that the electromagnetic wave absorption mechanism of the material is predominantly influenced by the presence of pores, sulfur-related defects, potential Fe–SX species, and Fe/Fe3O4–carbon heterogeneous interfaces. These results demonstrate that porous carbons synthesized via the hyper-crosslinking technique offer advantages such as high porosity and facile heteroatom doping, presenting a novel approach to integrating impedance matching with multiple loss mechanisms. This work may inspire expanding the application of functional porous carbon materials.