Ultralight‐Weight Graphene Aerogels with Extremely High Electrical Conductivity

Abstract

The integration of 2D graphene sheets into a porous and macroscopic structure is extremely attractive for application in several electrochemical fields. In this regard, for the first time, the synthesis of 3D graphene aerogels is reported by using a rapid, easy, cost‐effective, and scalable at industrial level methodology. These aerogels integrate the intrinsic properties of graphene with a high pore volume. To achieve this ultraporous graphene network, resorcinol/formaldehyde polymer with controllable porosity is employed as a binder and a cross‐linker material, and a graphene oxide solution provides the graphene building blocks. Two series of materials with and without catalyst for resorcinol/formaldehyde reaction and with different synthesis conditions and graphene contents are studied. The resulting graphene aerogels present low density, large macroporosity, and electrical conductivity values as high as 852 S m−1, with 97.58% of porosity, which is the highest value of electrical conductivity reported so far in the literature for ultralight‐weight graphene aerogels.

Reduced Graphene Oxide Aerogels Cartridges for Solid Phase Extraction of Benzotriazoles

“…Therefore, only the broad peak at 23.7° (2θ) can be appreciated in those patterns. On the other hand, all the thermally treated samples showed a better-defined band at 25° (2θ) ( Figure 2 a–c), which corroborates the reduction in GO [ 25 , 26 , 27 ]. The GO sheets present during the gelling of the RF network are prone to crosslink via covalent bonding through the GO oxygen functionalities.…”

“…The GO sheets present during the gelling of the RF network are prone to crosslink via covalent bonding through the GO oxygen functionalities. This has been illustrated in our recent publication [ 25 ]. During the carbonization, these covalent bonds will either break with the emission of volatiles or be transformed into sp 2 or sp 3 carbon structures.…”

“…The rGO aerogels were studied in the present work as a possible upgrade of the GSs for SPE [ 19 , 20 , 21 ] on the basis of the GAs properties found in our recent work [ 25 ]. Specifically, GAs had much better mechanical properties than GS, which was quite difficult to handle.…”

Structured Ultra‐Flyweight Aerogels by Interfacial Complexation: Self‐Assembly Enabling Multiscale Designs

“…[28,29] However, due to the poor rheological and mechanical integrity, the macroscale design of low-concentration GO-based suspensions, e.g., to fabricate structured ultralight or ultra-flyweight aerogel, remains an arduous challenge. [30] The incorporation of additives, such as surfactants, binders, and rheology modifiers, can address such challenges. However, these additives dramatically diminish the properties of the final products (conductivity, for example) and increase the density of the resultant aerogels.…”

Ultralight, Elastic, Hybrid Aerogel for Flexible/Wearable Piezoresistive Sensor and Solid–Solid/Gas–Solid Coupled Triboelectric Nanogenerator

“…The unique 3D porous structures of aerogels provide high porosity, ultralow density, and high specific surface area. [ 15 , 16 , 17 ] Conductive, compressible, and elastic aerogels have been considered as excellent candidates for fabricating flexible/wearable devices [ 18 , 19 , 20 , 21 ] such as piezoresistive sensors, [ 15 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ] and energy harvesting devices. [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ] The flexible and compress 3D porous structure of aerogels can provide large numbers of adjustable contact areas which can modulate the electrical resistance under the external pressure.…”