Tunable high-performance electromagnetic interference shielding of intrinsic N-doped chitin-based carbon aerogel

Abstract

Heteroatom doping of carbon aerogels is a promising strategy to dissipate electromagnetic waves (EMWs) and it is still a daunting challenge to establish the relationship between heteroatomic structure and EMI shielding performance. In our work, intrinsic N-doped biomass-based carbon aerogel was successfully prepared by freeze-drying and a specific two-stage pyrolysis using chitin and chitosan as carbon and nitrogen source. The content and type of doping elements and electrical conductivity could be accurately manipulated by controlling the content of precursors and carbonization temperature. The intrinsic N-doped induced a dipole polarization, and the unique three-dimensional porous architecture of biomass-based carbon aerogel was conducive to multiple reflection/scattering of EMWs. The as-prepared biomass-based carbon aerogel at 1300 °C exhibited an optimal EMI performance of 82 dB, and the absorption coefficients could be tuned in the range of 0.31–0.88. The excellent EMI performance originated from a variety of mechanisms involving conduction loss, dipole polarization loss, and interface polarization loss. The novel heteroatomic doping strategy not only provides new insight into the contribution of heteroatomic structure to EMI shielding performance, but also opens a new avenue to develop biomass-based carbon aerogels with tunable EMI shielding performances.