Core-shell Cr2O3 hollow spheres anchored reduced graphene oxide aerogel to boost electromagnetic wave absorption performance

Reduced graphene (rGO) aerogel shows great potential as electromagnetic (EM) wave absorbers due to its lightweight feature and strong EM attenuation ability resulted from high conductivity. However, excessive conductivity and sole EM wave loss mechanism of rGO aerogel make it difficult to balance impedance matching characteristic as well as EM attenuation characteristic, restricting the construction of broadband absorbers. Herein, serial transition metal ions doped core-shell Cr 2 O 3 hollow spheres were prepared and incorporated with rGO to resolve above issue. The introduction of hollow structured Cr 2 O 3 component not only retains lightweight but also induces multiple loss mechanisms to strengthen EM wave dissipation. It was found that species of doping element played significant role on determining EM wave absorption performance of composites. Thereinto, Co doped core-shell Cr 2 O 3 hollow spheres/rGO aerogel delivered the best EM wave absorbing capacity with effective absorption bandwidth of 6   GHz and minimum reflection loss of -57.06   dB. The excellent EM wave absorption performance originated from the best impedance matching characteristic and the strongest attenuation capacity due to Co doping. This work offers a novel insight into the preparation of lightweight and high-performance Cr 2 O 3 /rGO aerogel EM wave absorbing composites and its potential application area in the field of radar microwave stealth.