Obviously improved electromagnetic interference shielding performances for epoxy composites via constructing honeycomb structural reduced graphene oxide

Reduced graphene oxide with honeycomb structure (rGH) was successfully constructed and prepared by freeze-drying & thermal annealing using aluminium oxide (Al₂O₃) honeycomb as a template. The obtained rGH frameworks were then immersed into epoxy resins to fabricate the corresponding rGH/epoxy composites. The incorporated rGH could obviously enhance the electromagnetic interference shielding effectiveness (EMI SE) and electrical conductivity of the epoxy composites. When the mass fraction of rGH was 1.2 wt%, the obtained rGH/epoxy composites had the maximum EMI SE of 38.0 dB (at X-band) and electrical conductivity of 40.2 S/m, about 6.3 and 1340 times of the rGO/epoxy composites (6.0 dB and 0.03 S/m) with the same loading of rGO, respectively. Meantime, the introduction of rGH could be beneficial to improving the thermal stabilities of the rGH/epoxy composites.