Three-dimensional porous graphene-based composite materials: electrochemical synthesis and application

A general method for the fabrication of three-dimensional (3D) porous graphene-based composite materials is reported. This method involves two consecutive electrochemical steps. Firstly, 3D graphene (ERGO) porous material is prepared electrochemically by reducing a concentrated graphene oxide dispersion. Subsequently, the second component is electrochemically deposited onto this 3D ERGO matrix, yielding graphene-based 3D porous composite material. The prepared graphene-based composite materials have a conductive graphene network as the matrix, onto which the second component is homogeneously coated. Conducting polymers, noble metal nanoparticles and metal oxide were successfully incorporated into ERGO architectures, demonstrating the versatility of this method. Taking the ERGO–polyaniline composite as an example, the influence of deposition rate on the morphology of the composite was investigated. Finally, the application of the composite materials prepared with our method was discussed. The high surface area and low electrolyte transport resistance make these electrosynthesized composites suitable electrode materials for electrochemical devices. The ERGO–polyaniline composite electrode showed a high specific capacitance of 716 F g−1 at 0.47 A g−1, and this capacitance could be maintained at 502 F g−1 as the discharge current density was increased up to 4.2 A g−1.