Development of peanut husk carbon quantum dots and ferrite foil epoxy composite for EMI shielding at high frequency bands

In this study, a thin-walled epoxy biocomposite electromagnetic interference (EMI) shielding material was prepared using peanut husk carbon quantum dots and ferrite foil. This work aims to investigate how the biomass turned carbon material improvises the shielding effectiveness of ferrite foil-epoxy composites in X and Ku bands. The composite laminates were prepared by a room temperature hand layup method and cured to room temperature. The results of the study reveal that 45 vol. % ferrite foil increases relative permeability and dielectric loss for composite designation up to 4.62 and 0.072. Similarly, the highest relative permittivity and dielectric loss of composite designation EFC3, when compared to pure epoxy, are 65% and 66%, respectively. The EFC1 offers high magnetization of 728 E-6 emu with 1 vol. % of carbon quantum dots. Similarly, the EFC3 offers a maximum microwave shielding for both E and J bands of about − 52.8 dB and − 54.7 dB, which contains 5 vol. % of carbon quantum dots. Moreover, adding 45 vol. % ferrite foil with 3 vol. % of carbon quantum dots improved the tensile and flexural strengths to 138.4 MPa and 18.2 MPa. Such EMI shielding composites could be used in microwave gadgets, radar, telecommunication devices and aerospace.