In this study, an Fe-Co alloy is coated with carbon and decorated on a holey reduced graphene oxide nanosheet (FeCo@C/HRGO) composite. The structure is synthesized using liquid-phase reduction and hydrothermal processes followed by high-temperature calcination. The FeCo@C/HRGO composite is identified and characterized using XRD, XPS, Raman spectroscopy, TEM, and SEM. This novel composite exhibits excellent electromagnetic-wave absorption properties. The maximum reflection loss for FeCo@C/HRGO reaches -76.6 dB at 16.64 GHz with a thickness of 1.7 mm. The R-L below -10 dB reaches 14.32 GHz for a thickness of 1.7-5.0 mm. This confirms that microwave absorption of FeCo@C can be substantially improved upon decoration with HRGO nanosheets. (C) 2019 Elsevier Inc. All rights reserved.