High-performance self-assembled graphene hydrogels prepared by chemical reduction of graphene oxide

Three-dimensional self-assembled graphene hydrogels (SGHs) have been fabricated by chemical reduction of graphene oxide (GO) with sodium ascorbate. The SGHs were characterized by scanning electron microscopy, rheological tests, electrical conductivity measurements, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. Results indicate that the reduction of GO promotes the assembly of graphene sheets. The SGHs are electrically conductive (1 S·m−1) and mechanically strong and exhibit excellent electrochemical performance. In 1 mol·L−1 aqueous solution of H2SO4, the specific capacitance of SGHs was measured to be about 240 F·g−1 at a discharge current density of 1.2 A·g−1.