▎ 摘　　要

The high entropy alloy is a powerful material due to its high hardness, strength, magnetic performance, corrosion resistance, and temperature stability. Moreover, when combined with reduced graphene oxide (rGO), it formed a novel material for electromagnetic (EM) absorption. In this work, monodisperse high entropy alloy nanocrystals combined with rGO to create a new type of high entropy alloy/rGO EM absorp-tion material. A colloidal synthesis strategy was used to prepare high entropy Pt18Ni26Fe15Co14Cu27 nanocrystals with a small size of around 3.3 nm. These nanocrystals then in situ grew uniformly on the surface of rGO to form Pt18Ni26Fe15Co14Cu27/rGO nanocomposite, which were then characterized and tested for EM absorption performance. Compared to the pure high entropy Pt18Ni26Fe15Co14Cu27 nanocrystals, the composite exhibited an improved EM absorption performance with a minimum reflec-tion loss of -41.8 dB at 4.9 GHz and efficient EM wave absorption up to a bandwidth of 2.5 GHz in the 9.4-11.9 GHz band. This novel high entropy alloy/rGO composite has great potential to be used as an excellent material for EM wave absorption. (c) 2023 Elsevier Inc. All rights reserved.