Robust graphene-based monoliths of homogeneous ultramicroporosity

Abstract

Graphite oxide (GO) and graphene monoliths were prepared using the unidirectional freezing of GO water suspension. These materials were saturated with a poly(4 ammonium styrene sulfonic acid) water soluble polymer and then carbonized at 1123 K. This process increases significantly the materials strength and density. A uniform deposition of the polymer-derived carbon on the external layers of the graphene sheets of the monolith was found. The carbon from polymer not only provided more contact between the graphene sheets but apparently increased the overall graphitization level (based on Raman spectra). The modification decreased the electrical resistance by one order of magnitude compared to that of the graphene monolith. N2 adsorption at 77 K showed that the thus-treated graphene monoliths has quite homogenous pores with the pore width of 0.7 nm. These pores combined with large transport pores and conductive properties make the monoliths tested the promising materials for separation, energy storage and/or gas sensing. The tunability of the properties and pore structure of the robust graphene untramicroporous monolith through the control of chemistry of the initial GO monolith was shown.

Functionalized and Platinum-Decorated Multi-Layer Oxidized Graphene as a Proton, and Electron Conducting Separator in Solid Acid Fuel Cells

“…This could be changed by introducing a graphene separator between the CDP and platinum layers. Graphene attracted considerable interest because of its unique electrical, thermal, and me-chanical properties [66][67][68][69][70][71][72][73][74]. These properties are affected by the graphene layers number, whereas the conductivity decreases with the increase in the graphene thickness [75][76][77][78][79][80][81][82][83][84].…”

Preparation of graphene/vanadium oxide nanocomposite monolith and its electrochemical performance

“…Some V 2 O 5 /G composites for supercapacitors and LIBs have been prepared. It is known that the monolith form electrode materials have intriguing advantages over powdered form such as high electrical and thermal conductivities, high density storage, no intergranular barriers, more well-accessible macroporous channels and easy handling when used for supercapacitors and LIBs [23,24]. However, there are rare reports on the G/V 2 O 5 nanocomposites monolith with novel interpenetrated structure for supercapacitors and LIBs.…”