Graphene aerogels via hydrothermal gelation of graphene oxide colloids: Fine-tuning of its porous and chemical properties and catalytic applications

Recently, 3D graphene aerogel has garnered a high interest aiming at benefiting of the excellent properties of graphene in devices for energy storage or environmental remediation. Hydrothermal gelation of GO dispersion is a straightforward method that offers many opportunities for tuning its properties and for processing it to devices. By adjusting hydrothermal gelation and drying conditions, it is possible to tune the density (from similar to 3 mg cm(-3) to similar to 2 g cm(-3)), pore volume, pores size (micro to macropores), pore distribution, surface chemical polarity (hydrophobic or hydrophilic), and electrical conductivity (from similar to 0.5 S m(-1) to S cm(-1)). Besides other well explored applications in energy storage or environmental remediation, graphene aerogels have excellent prospects as support for catalysis since they combine the advantages of graphene sheets (high surface area, high electrical conductivity, surface chemistry tunability, high adsorption capacity.) while circumventing their drawbacks such as difficult separation from reaction media or tendency to stacking. Compared to other 3D porous carbon materials used as catalyst support, graphene aerogels have unique porous structure. The pore walls are the thinnest to be expected for a carbon material (the thickness of monolayer graphene is 0.335 nm), hence leading to the highest exposed surface area perweight and even per volume for compacted aerogels. This has the potential to maximize the catalytic site density per reactor mass and volume while minimizing the pressure drop for continuous reactions in flow. Herein, different strategies to control the porous texture, chemical and physical properties are revised alongwith their processability and scalability for the implementation into different morphologies and devices. Finally, the application of graphene aerogels in the catalysis field are overviewed, giving a perspective about future directions needing further research. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

3D graphene aerogels have gained significant attention for their excellent properties in energy storage and environmental remediation applications. By adjusting hydrothermal gelation and drying conditions, the properties of graphene aerogels can be tuned, offering a wide range of potential applications. The unique porous structure and high surface area of graphene aerogels make them promising materials for catalysis and other applications.