In situ generation of TiO2 in graphene aerogel and its epoxy composite for electromagnetic interference shielding performance

Multi-component composite can effectively improve the electromagnetic interference shielding effectiveness (EMI SE) due to the synergistic effects. Herein, graphene aerogel (GA) provides a three-dimensional network framework and in situ generation of titanium dioxide (TiO2) on its network layer by the sol-gel method. After microwave irradiation reduction, the titanium dioxide/microwave-reduced GA (TiO2/MRGA) was immersed in epoxy resin solution and cured to obtain its composite. The existence of the Ti-O-C bond proves the favorable combination of TiO2 and MRGA. Under electromagnetic radiation, MRGA and TiO2 generate a synergistic effect to improve the EMI SE of the composite. When the mass ratio of TiO2 to MRGA is 1.5:1 (2.1 wt%+1.4 wt%), the composite exhibits a maximum EMI SE of 32.5 dB in the X band. Moreover, when the mass ratio of TiO2 to MRGA is in the range of 1 to 1.8, the average EMI SE of the composites increases by 37% compared with that of the MRGA/Epoxy composite. The research indicates that this kind of EMI shielding composite has enormous application potential.