Multistage coupling of interface and core–shell engineering of a cobalt-based heterostructure for integration of multiple electromagnetic absorption

Abstract

To avoid the electromagnetic radiation pollution derived from the rapid development of radio technology, designing an absorber which integrated multiple properties with vigorous reflection loss (RL), wide bandwidth, thinness and a low filling ratio is paramount yet extremely challenging. Herein, a heterostructure fabricated by the coupling of interface engineering and core–shell concept is reported, namely, cobalt-based magnetic nanospheres uniformly anchored on the surface of reduced graphene oxide (rGO). A zeolitic imidazolate framework attracted on the surface of GO was exploited as initial precursor to obtain the absorber via polydopamine (PDA) coating and subsequent pyrolysis. The density functional theory (DFT) calculations confirm that the heterostructure constructed using an interfacial electron interaction contributed to the interfacial and dipole polarization, whereas the dielectric loss is further improved. As a result, the RL of −44.64 dB and the effective absorption bandwidth of 5.76 GHz are simultaneously realized by using an absorber at a low filling ratio of 15 wt%, corresponding to a thickness of 1.92 mm. Both the experimental and radar cross section (RCS) simulation demonstrate that the absorber can effectively suppress the electromagnetic (EM) scattering. Therefore, this work expands the prospects for precise synthesis of multifunctional absorbers and shows great promise for the development of frontier absorbers for anti-EM interference.