Organic solvents-enabled hydrothermal preparation of graphene hydrogels

The graphene hydrogels (GHGs) could be prepared via hydrothermal process using graphene oxide (GO) hydrosol. However, the formation of GHGs is unavailable when the GO concentration is low. In this work, we successfully address this problem with the aid of some organic solvents such as tetrahydrofuran, acetone and ethanol. The as-obtained GHGs have different mesopore structure and interior microstructure depending on the organic solvents used. Ethanol-enabled GHGs (eGHGs) show a cross-linked three-dimensional (3D) network structure composed of random dispersed graphene, and greatly enhance the cycling stability of Si nanoparticles as an anode material for lithium ion batteries. This work extends the possibility of synthesizing network graphene macroform.