Biopolymer nanofiber/reduced graphene oxide aerogels for tunable and broadband high-performance microwave absorption

Natural biopolymer cellulose nanofiber (CNF)/reduced graphene oxide (rGO) hybrid aerogels are developed for light-weight and high-efficiency microwave absorption (MA) materials. To evaluate the MA performance, CNF/rGO composites with different rGO/CNF ratios are fabricated, and the microstructure of CNF/rGO composites is tuned by changing the concentration of CNF precursor solution. It demonstrates that the MA performance is determined by not only the rGO addition but also the concentration of CNF aqueous precursor solution, evidencing the important role of microstructure of CNF/rGO composites in MA performance. The CNF/10% rGO composite prepared by 0.75% CNF solution exhibits superior MA performance with the maximum reflection loss (RL) of −40.64 dB and effective absorption bandwidth (EAB) (RL < −10 dB) up to 7.72 GHz at the thickness of 2.5 mm. This work provides an effective strategy to design polymer/rGO hybrid materials for improving microwave absorption properties with tunable frequency and broad absorption bandwidth.