Synergetic effect of reduced graphene oxide and reticulated open-cell aluminum hybrid composite foam for high-performance electromagnetic wave absorption

In the present work, open-cell aluminum-reduced graphene oxide composite (Al-rGO) foam with varying concentrations of reduced graphene oxide (rGO) was fabricated through the template method and foam's electrical, mechanical, and electromagnetic shielding behavior was studied. The reticulated Al-rGO foam allows the electromagnetic wave (EMW) to go inside the structure and resulting in multiple scattering which enhances the wave absorption capacity of the material. Adding rGO into open-cell aluminium foam (OCAF) enhances its shielding properties, particularly the absorption component. The Al-rGO3 foam shows a total EMI shielding of similar to 62 dB at 8.4 GHz frequency and out of which 61.34 dB (> 99% of total shielding) is the absorption component. The Al-rGO foam also exhibited maximum compressive strength of 2.96 MPa and EMI shielding of similar to 62 dB at 1.5 wt% rGO, even though the electrical conductivity reduces with rGO content. This may be due to a greater degree of multiple scattering of EMW inside the cellular structure and different energy losses at rGO-Al interfaces. This work shows a new way to use the lightweight metallic structure for high EMW absorption applications with good mechanical stability in the defense and aerospace sectors.