Reduced graphene oxide-ferrite microcomposites based on petung bamboo (dendrocalamus asper) charcoal and iron sand as lightweight microwave absorbing materials

Reduced graphene oxide-ferrite (rGO/Fe₃O₄) microcomposites as lightweight microwave absorbing materials has been successfully synthesized from petung bamboo and iron sand by mechanical mixing method at different rGO content (0:1, 1:0, 1:1, 1:2, 1:3, 2:1 and 3:1 wt%). Reduced graphene oxide as dielectric material was synthesized from petung bamboo charcoal using carbonization method and ferrite as magnetic material was synthesized from iron sand using extraction-milling method. Structural characterization by x-ray Fluorosence, Fourier Transform Infrared, Vibrating Sample Magnetometry, x-ray Diffraction, Scanning Electron Microscopy proved that micrometer sized reduced graphene oxide ferrite in the microcomposites was responsible for the ferromagnetic behavior of the composites. The reflection loss of microcomposites measured in the microwave frequency range of 8-12 GHz using a Vector Network Analyzer. The results showed that at the micro scale, rGO had a higher absorption power with maximum reflection loss (RL _m ) value of −21.81 dB at matching frequency (f _m ) 10.85 GHz compared with Fe₃O₄ (RL _m value of −9.25 dB at f _m = 10.60 GHz) at thickness of 1 mm. The rGO/Fe₃O₄ (2:1 wt%) microcomposites microwave absorber shows the optimum absorption with maximum reflection loss value of −16.51 dB at matching frequency (f _m ) 10.74 GHz at thickness of 1 mm. The use of natural materials and the controlled rGO/Fe₃O₄ microcomposites structure with simple synthesis methods, which the urgent need for developing high performance lightweight microwave abrsorbing materials and are environmentally friendly.