Electrochemical reduction of bulk graphene oxide materials

Electrochemical reduction has been used to prepare graphene materials with one-dimensional (1D) to three-dimensional (3D) architecture. The electron acts as the reducing agent directly during the electrochemical reduction, which gives efficient reduction with the conservation of the original structure of the graphene oxide (GO) materials. It provides a simple method to process the GO nanosheets into designed materials using it in aqueous solution, and with an electrochemical reduction to realise the functional graphene materials. This method avoids using graphene nanosheets as the feedstock which are difficult to dissolve in a solvent, especially at a high concentration. 1D fiber, two-dimensional thin film on glass or poly(ethylene terephthalate) (flat or curved), and 3D graphene sponge have been successfully prepared, and the dynamics of the reduction was also studied. Electrochemical reduction is especially suitable for reducing composites of GO and polymers, a process which can be carried out at room temperature without any chemical reducing agents. A silk fibroin/electrochemically reduced GO (SF/ERGO) composite film was prepared using homogeneous reduction, which showed excellent mechanical properties and electrical conductivity. Electrochemical reduction is a general method to prepare many kinds of graphene materials for a wide range of applications.