Bifunctional Reduced Graphene Oxide/V2O5 Composite Hydrogel: Fabrication, High Performance as Electromagnetic Wave Absorbent and Supercapacitor

Multifunctional graphene hydrogels have attracted great attention aimed at practical applications. Herein, the novel and bifunctional composite hydrogel containing reduced graphene‐oxide nanosheets (RGO) and V2O5 nanobelts (RGO/V2O5) is successfully prepared for the first time. Surprisingly, tridimensional (3D) RGO/V2O5 composite hydrogels cannot only be used as high‐performance electromagnetic (EM) wave absorbents; they also exhibit excellent properties suitable for supercapacitor electrodes. The composites exhibit a maximum absorption of up to −21.5 dB. In particular, a composite hydrogel showed a bandwidth of 6.63 GHz, corresponding to a reflection loss at −10 dB, which opens the possibility for the use of 3D graphene with other functional nanomaterials as lightweight and high‐performance EM wave absorption materials. Remarkably, the composite hydrogel is capable of delivering a high specific capacitance of about 320 F g−1 at a current density of 1.0 A g−1. Beyond graphene: A novel and bifunctional 3D composite hydrogel containing reduced graphene‐oxide nanosheets and V2O5 nanobelts is presented. This bifunctional material exhibits excellent properties as electromagnetic wave absorbent and can also be used as a supercapacitor for a two‐electrode system delivering a high specific capacitance of about 320 F g−1.