Tailored construction of magnetic hollow glass microspheres/N-doped carbon toward lightweight and efficient electromagnetic wave absorption

Hollow composites possess several merits as electromagnetic wave absorbers, such as lightweight, abundant heterointerfaces and good impedance matching. Herein, the magnetic hollow glass microspheres (HGMs)@Ndoped carbon (NC) composites were designed and fabricated stemming from polydopamine (PDA) and FeCo-layered double hydroxide (LDH) as modifier of HGMs to balance the impedance matching and attenuation capacity. The derivatives of FeCo-LDH adjust the magnetic loss, and the proper content could endow the hybrids with well-matched impedance. As expected, the dielectric/magnetic synergistic composites-HGMs@NC@LDH derivatives (LDD), exhibit good comprehensive absorption abilities. The minimum reflection loss of these composites can achieve 46.7 dB. Especially for the sample derived from the composite of HGMs@PDA:FeCo-LDH = 1:1, it showed a wide effective absorption band of 5.12 GHz and minimum reflection loss of -37.8 dB at 2.2 mm with just 10 wt% filler loading. The outstanding performances can be mainly attributed to the good impedance matching and the enhanced synergistic effect of dual-loss as well as the introduced appropriate conduction loss. This work proposes a precise inspiration in developing hollow dual-loss absorbers with the balance of well-matched impedance and strong attenuation ability.