One-step rapid achieving O-SWCNHs@SiO2 core–shell heterostructures with tunable electromagnetic absorption performance via arc plasma

Core–shell heterostructures are promising functional materials with prospective applications in the electromagnetic wave (EMW) absorption field. Herein, according to the bottom-up synthesis approach, the O-SWCNHs@SiO2 core–shell nanoarchitecture materials with ultra-low bulk density (23–32 mg·cm−3) are rapidly in situ synthesis by using DC arc plasma. The SiO2 is wrapped flatly on the outer surface of the O-SWCNHs spheres-core, forming a unique heterostructure. The introduction of SiO2 shell causes the ample interfacial of SWCNHs/SiO2 that regulates interfacial polarization and impedance matching. Meanwhile, the in-situ doping of oxygen and silicon atoms enhances the dipole polarization. The SWCNHs@SiO2 possesses excellent tunable EMW absorption performance. The minimum reflection loss (RLmin) peak can move from a high frequency (13.9 GHz, – 61.78 dB) to a low frequency (6.48 GHz, – 59.85 dB), and the RL curve lower than −10 dB can cover 88.8 % (3.8–18 GHz) of the measuring frequency. The effective bandwidth and RL are superior to most composite absorbers with SWCNHs or SiO2 components. Overall, this work presents a simple and fast method for creating core–shell heterostructure that may be used as highly effective lightweight EMW absorbers with adjustable absorption performance.