A Universal Method for the Preparation of Dual Network Reduced Graphene Oxide–Ceramic/Metal Foam Materials with Tunable Porosity and Improved Conductivity

Inorganic porous materials have found a great many applications in fields such as filtration, catalysis, and so forth. However, most of these materials have been prepared using complicated template and foaming methods and furthermore in many cases suffer from low electrical and thermal conductivity. Herein, we developed a universal and simple method for the synthesis of dual network reduced graphene oxide–ceramic/metal foam materials from commercial powders directly with graphene oxide as a 2D dispersant following a two-step process (solvothermal and partial sintering). This approach leads to the formation of a three-dimensional and interpenetrating dual network of both reduced graphene oxide and inorganic material. Importantly, this method not only is rather scalable but can also be applied universally for various ceramic materials, such as Al2O3 and TiO2, and even metals such as Al and Cu. Furthermore, the material’s porosity can be controlled by varying sintering temperatures and using different sizes of starting materials, ranging from several nanometers to a dozen micrometers. Because of the dual network architecture of both reduced graphene oxide and inorganic components, these materials exhibit multiple functions such as high porosity, improved electrical conductivity, and so forth. These results thus offer a general platform from various commercial inorganic powder materials directly for preparing porous but mechanically stable bulk materials, which are in high demand for catalysis, filtration, conductive ceramic, and porous electrode materials.