Enhanced microwave absorption properties of reduced graphene oxide/TiO2 nanowire composites synthesized via simultaneous carbonation and hydrogenation

High-performance microwave absorbing materials of reduced graphene oxide (RGO) combined with hydrogenated TiO2 nanowires (h-TiO2nw) were prepared via a solvothermal and annealing method, in which carbonation and hydrogenation processes were achieved simultaneously. The incorporation of h-TiO2nw not only strengthened the interfacial polarization by introducing a large number of interfaces with RGO, but also made great contributions to the impedance matching of RGO/h-TiO2nw composites with air. By adjusting the weight content of h-TiO2nw, the complex permittivity of the composites could be well-controlled and an excellent microwave absorption performance was realized. For the absorber/paraffin mixture with an ultralow filler content (2 wt%), a minimum reflection loss value of -51.5 dB at 15.1 GHz and a broad effective absorption bandwidth of 6.46 GHz were achieved under the same small thickness of 2.7 mm. Such performance exhibits great advantages compared to most graphene-based materials in the literature. These results demonstrate that such RGO/h-TiO2nw composites can be potential candidates for lightweight, broadband, and strong microwave absorption materials.

Automated summary

High-performance microwave absorbing materials were prepared by combining reduced graphene oxide with hydrogenated TiO2 nanowires. By adjusting the weight content of TiO2 nanowires, the composites exhibited excellent microwave absorption performance and controlled complex permittivity.