graphene foam is an emerging material with a broad range of potential applications in energy storage, chemical sensing, environmental purification and chemistry. It is a porous, 3D version of the 2D sheet of carbon that is conventional graphene and has the same properties: super-strong, very high electron mobility and excellent conductivity of heat.
Typically, graphene foam is produced using chemical vapour deposition by introducing carbon containing gases such as methane and nitrogen to a metal foam substrate (typically nickel or copper). Once the reaction has completed, the foam is removed and the carbon atoms are etched away to form a thin layer of graphene.
Researchers at Purdue University have developed a new graphene-based thermal switch that can dynamically trap heat when it’s cold or allow it to escape when it’s hot. This is a good thing for electronics, which are sensitive to both high and low temperatures.
This method of producing N-doped graphene foam is particularly promising as it involves a fast and simple process. The obtained materials show good quality with no defects.
They are also environmentally friendly and can be made from plant-derived feedstocks, such as powdered cellulose and lignin. Moreover, they have the same properties as regular graphene foams: high conductivity and mechanical strength.
The synthesis of graphene foams by the microwave method is also fast and efficient, which can be achieved with various solvents such as ethanol or dimethylformamide. The obtained materials are not agglomerated and exhibit N-rich bridges between graphene flakes that enable electron transfer throughout the whole mass of material.
