Zn,N-codoped mesoporous carbon particles/carbon fibers for wide-band electromagnetic wave absorption

Carbon fibers with low density, high stability and unique structural characteristics are a huge potential electromagnetic wave absorber. However, it is difficult to achieve wide-band absorption of the carbon fibers due to their impedance mismatching and limited loss factors. Herein, we develop a facile method to fabricate Zn,N-codoped carbon particles/carbon fiber (N,Zn-PNP/NCF). The Zn,N-codoped strategy can cause the distortion of electron clouds of C atoms and the generation of defect sites, which improve the electromagnetic wave absorption performance of carbon fibers. As a result, the optimal N,Zn-PNP/NCF show excellent absorption property with an effective absorption bandwidth of 5.89 GHz at the thickness of 2.0 mm, which is significantly superior to the ordinary N-doped carbon material and most of reported carbon-based absorbers. Theoretical calculations and the experimental results suggest that the Zn,N-codoping along with the interfaces between carbon particles and carbon fibers can effectively enhance the polarization loss capability of carbon fibers due to the charge redistribution caused by the Zn and N heteroatoms. Besides, based on the dielectric characteristic of the optimal N,Zn-PNP/NCF, a pressure response absorber (PSA) is designed, which can realize the selective absorption in the wide frequency region.