Formation of 3D graphene foams on soft templated metal monoliths

Abstract

Graphene foams are leading contenders as frameworks for polymer thermosets, filtration/pollution control and for use as an electrode material in energy storage devices, taking advantage of graphene's high electrical conductivity and the porous structure of the foam. Here we demonstrate a simple synthesis of a macroporous 3D graphene material templated from a dextran/metal salt gel, where the metal was cobalt, nickel, copper, and iron. The gel was annealed to form a metal oxide foam prior to a methane chemical vapour deposition (CVD). Cobalt metal gels were shown to afford the highest quality material as determined by electron microscopy (SEM and TEM) and Raman spectroscopy.

Nitrogen Adsorption on Graphene Sponges Synthesized by Annealing a Mixture of Nickel and Carbon Powders

“…A similar range of values of the graphene layers was shown on the multilayer graphene obtained on transition-metal foams by the chemical vapour deposition (CVD) method [10]. The dissolution of carbon in the metal takes place using CVD process [10] and Ni -carbon powder annealing methods [1]. When a carbon atom precipitates on the metal, at the cooling stage, the formation of multilayer graphene sheets occurs.…”

<p>Assessing Cobalt Metal Nanoparticles Uptake by Cancer Cells Using Live Raman Spectroscopy</p>

“…Under low laser power, the Raman pattern corresponds to face-centred cubic cobalt metal as illustrated by the blue spectrum in figure 3c. 44,45 The Raman pattern in Figure 3C (red spectrum) corresponds to the Co 3 O 4 crystalline structure. Consequently, it confirms that the laser irradiation provokes the spontaneous oxidation of the Co MNPs.…”

Platinum-free, graphene based anodes and air cathodes for single chamber microbial fuel cells

“…38 However, the mesh template, usually copper or nickel, often requires intensive procedures including an acid etching step for removal (which can create chemical residuals), and gas precursors ( e.g. methane) for CVD, 39 substantially increasing costs of electrode fabrication. Pristine graphene flake based aerogels created by freeze gelation of solvent/graphene solutions offer a simple alternative, with superior electrical properties to GO/RGO aerogels.…”