Highly Elastic and Conductive N-Doped Monolithic Graphene Aerogels for Multifunctional Applications

Abstract

The simple synthesis of ultralow-density (approximate to 2.32 mg cm(-3)) 3D reduced graphene oxide (rGO) aerogels that exhibit high electrical conductivity and excellent compressibility are described herein. Aerogels are synthesized using a combined hydrothermal and thermal annealing method in which hexamethylenetetramine is employed as a reducer, nitrogen source, and graphene dispersion stabilizer. The N-binding configurations of rGO aerogels increase dramatically, as evidenced by the change in pyridinic-N/quaternary-N ratio. The conductivity of this graphene aerogel is approximate to 11.74 S m(-1) at zero strain, whereas the conductivity at a compressive strain of approximate to 80% is approximate to 704.23 S m(-1), which is the largest electrical conductivity reported so far in any 3D spongelike low-density carbon material. In addition, the aerogel has excellent hydrophobicity (with a water contact angle of 137.4 degrees) as well as selective absorption for organic solvents and oils. The compressive modulus (94.5 kPa;. rho approximate to 2.32 mg cm(-3)) of the rGO aerogel is higher than that of other carbon-based aerogels. The physical and chemical properties (such as high conductivity, elasticity, high surface area, open pore structure, and chemical stability) of the aerogel suggest that it is a viable candidate for the use in energy storage, electrodes for fuel cells, photocatalysis, environmental protection, energy absorption, and sensing applications.