Ultrafast Synthesis of Multifunctional N-Doped Graphene Foam in an Ethanol Flame

Abstract

A hard template method to prepare N-doped graphene foams (NGF) with superfast template removal was developed through a pyrolyzing commercial polyurethane (PU) sponge coated with graphene oxide (GO) sheets in an ethanol flame. The removal of the template was fast and facile, and could be completed in less than 60 s in an open environment. The synthesized graphene foams consisted of a unique structure of 3D interconnected hollow struts with highly wrinkled surfaces, and the morphology of the hollow struts could be tuned by controlling the GO dispersion concentration. The foams showed high hydrophobicity and were used as absorbents for a variety of organic solvents and oils. The unique NGF structure afforded a high absorption rate and capacity, and a remarkable 98.7% pore volume of the foam could be utilized for absorption of hexane, exhibiting one of the highest capacity values among existing absorptive counterparts. The N-doping brought higher capacitive performance than conventional graphene foams prepared by chemical vapor deposition on nickel foam templates. The NGFs also displayed high elasticity and could recover completely after 50% compressive strain. Owing to easy availability and reduction environment of the flame, complete thermal decomposition of the PU sponge and highly porous open-cell structure, and flame resistance of the graphene foam, the present flame method was demonstrated to be a simple, effective, and ultrafast approach to fabricate ultra-low-density NGFs with good electromechanical response, excellent organic liquid absorption, and high-energy dissipation capabilities.

3D Graphene‐Based H2‐Production Photocatalyst and Electrocatalyst

“…Recently, a fast and feasible template‐assisted method for the synthesis of N‐doped graphene foam (NGF) was developed ( Figure 7 a). [ 50,51 ] Firstly, a commercially available melamine sponge with continuous 3D macroscopic network was immersed into GO suspension to guarantee the sufficient absorption and diffusion of GO sheets (Figure 7b–e). Afterward, the melamine skeleton in GO sheets absorbed melamine sponge was burnt and removed thoroughly by an ethanol burner, leaving behind a 3D graphene foam with the interconnected and tubular structure (Figure 7f,g).…”

Silane bonded graphene aerogels with tunable functionality and reversible compressibility

“…It should be noted that the sensitivity (∆R/R 0 ) at different strain amplitudes for our silane-b-RGO aerogels compared against other 3D carbon materials reported in the literature [13, 21, 26-28, 32, 35, 68] is shown in Table. S3. We can tailor the sensitivity of silane-b-RGO aerogel to very high levels (60-80% at ε=60%), surpassing 3D cellular materials fabricated from graphene [69] or CNT aerogels [13] and graphene foam [70] with similar densities and conductivities. The change of normalized electrical resistance (∆R/R 0 ) value of the silane-b-RGO aerogel exhibits only a slight change after multiple compression cycles (Fig.…”

Multifunctional Stiff Carbon Foam Derived from Bread

“…Although graphene sheets have been attracted tremendous interests and have been widely used in making monolithic foams, 1,[9][10][11][12][13][14] the prepared foams are associated with conspicuous problems of poor mechanical stability. Further, fabrication graphene foams requires various complex operations, long time, and relatively high costs, making largescale production of graphene foams quite difficult.…”