Lightweight porous carbon/rGO/Ni chain composite with excellent microwave absorption performance and multi-functional properties

Melamine foam was converted into porous carbon by high-temperature carbonization and then composited with reduced graphene oxide(rGO) and Ni chains by impregnation, freeze-drying, and high-temperature reduction, resulting in porous carbon/rGO composites and porous carbon/rGO/Ni chain composites. The electrical con-ductivity, wettability and wave-absorbing properties of the composites were investigated. The results show that the electrical conductivity of the composites is significantly improved, up to 2.29 mS/mm. This is because rGO has good electrical conductivity. In addition, When the thickness is 5.5 mm, the minimum reflection loss of the MF-3rGO sample of -29.9 dB is obtained at 5.84 GHz and the effective bandwidth is 2.08 GHz. This is because rGO nanosheets have strong conductance loss. The addition of a small amount of Ni chains can tune the impedance matching ability of the composites. When the Ni chain content is 0.12 g, the optimum reflection loss of the MF-3rGO-0.12Ni is -32.6 dB at 16.72 GHz with a thickness of 2 mm, and the effective bandwidth is 4 GHz. Meanwhile, the porous carbon/rGO composites and porous carbon/rGO/Ni chain composites have good hydrophobicity and can be used in humid environments. Therefore, the porous carbon composites prepared by melamine foam can be widely used in the field of electromagnetic wave absorption.