Effect of different metal ratios on the synthesis, morphology and microwave absorption properties of DDM–RGO@Co1–xFex–LDH porous composites

The construction of multihollow lightweight wave absorbing materials is a future goal. Layered double hydroxides (LDHs) offer a great potential for electromagnetic wave absorption given their lamellar texture and tunable bimetallic composition. In this study, CoFe–LDH was grown on 4,4'-diaminodiphenylmethane-modified reduce graphene oxide (RGO) surfaces through a hydrothermal method, and composites with different morphologies and wave-absorbing properties were obtained at varying molar ratios of Fe to Co in CoFe–LDH. When Fe: Co=5:5, CoFe–LDH flakes grew uniformly on the RGO surface, and the composite exhibited an excellent microwave absorption performance with a minimum reflection loss of –60.0 dB and effective absorption bandwidth (EAB) of 4.4 GHz. When Fe: Co=3:7, the composite can obtain a maximum EAB of 5.12 GHz at a matched thickness of 1.82 mm.