The continued development of reticulated vitreous carbon as a versatile electrode material: Structure, properties and applications

Abstract

The limitations of 2-dimensional electrodes can be overcome by using threedimensional materials having sufficient porosity and active area while offering moderate mass transport rates and a relatively low pressure drop at controlled electrolyte flow rate. In concept, a wide variety of metal, ceramic and composite materials are possible but restrictions are imposed by the need to avoid materials degradation, while maintaining adequate electrical conductivity, sufficient robustness and the possibility of facile scale-up. Despite its fragility, one of the traditional electrode materials used as a porous, 3-dimensional electrode is carbon foam, particularly in the 97% vol. porous form of reticulated vitreous carbon, RVC. A timeline indicates that the history of this material dates back over 50 years to the mid1960s, when it was primarily used as an uncoated material in small-scale, laboratory electroanalysis. Surface modification and diverse coatings have considerably extended the use of RVC. Recent applications are found in sensors and monitors, electrosynthesis, environmental processing and energy conversion. This review highlights the fundamental structure and summarises the physicochemical properties of RVC. Fluid flow through various porosity grades of the material, their active electrochemical area and rates of mass transport are quantified. The diverse applications of RVC in energy conversion, environmental treatment and electrosynthesis are illustrated by selected examples from the authors' laboratories and others over the last 30 years. Recent research on coated RVC, energy conversion environmental remediation and sensors is highlighted. Critical areas deserving further research and development are proposed.

High‐Potential Metalless Nanocarbon Foam Supercapacitors Operating in Aqueous Electrolyte

“…The importance of the Gra/CNT foam lies in four aspects: (1) high potential ranges (1–2.5 V) resulting from enhanced hydrophilicity, capability of hydrogen adsorption, and antioxidation due to functional group attachment; (2) capacitance enhancement due to the pseudocapacitive effects of the functional groups; (3) graphite foam serves as the light weight current collector with low density compared to traditional Al foils and the other metal substrates; (4) binderless electrode with active materials directly grown on the current collector. Although the ratio of the active materials (i.e., CNTs) to the current collector (i.e., graphite foam) is not optimized in this case, the relatively lower density of the graphite foam (≈0.4–0.45 g cm −3 ) compared to the traditional Al foils (2.7 g cm −3 ) could inspire the plausible alternatives which would benefit the future researches on low‐weight and low‐cost current collectors without the utilization of sacrificial templates and CVD processes, such as the reticulated vitreous carbon foam, to improve the energy and power densities of the practical devices.…”

Effect of Silver Particles Electrodeposited on Reticulated Vitreous Carbon for Nitrate Reduction

“…The electrode material is an important variable for the nitrate electroreduction process and the development of new electrodes to improve their catalytic activity is a challenge (4). The use of reticulated vitreous carbon as working electrode has shown some advantages such as good conductivity, high surface area, chemical stability and low cost (5). Cooper and silver electrodes present good activity for the electroreduction of nitrate (4), therefore the deposition of these metals onto carbon electrodes to enhance the catalytic activity have been tested with good results (6,7,8).…”

Developments in electrode design: structure, decoration and applications of electrodes for electrochemical technology

“…Two approaches to achieving improved electrode surface properties by modifying existing structures are: Hybrid porous, 3D electrodes. Reticulated vitreous carbon (RVC) foam electrodes have been reviewed extensively . Possible ways of modifying such porous structures include: depositing high surface area, and active nanoparticles on the surface, combining the foam with a fibrous or felt structure .…”

“…Reticulated vitreous carbon (RVC) foam electrodes have been reviewed extensively. 23,24 Possible ways of modifying such porous structures include: depositing high surface area, and active nanoparticles on the surface, combining the foam with a fibrous or felt structure. 25 An example of the former is the deposition of gold nanospheroids, by sputtering, onto a nanoporous array of TiO 2 on a titanium foil, felt or mesh surface.…”