What is reduced graphene oxide (rGO)?

Nanomaterials are materials on the nanometre scale, where a nanometre is one billionth of a metre. In this fascinating tiny world, materials exhibit unique properties due to their size and structure at the nanometre scale.

Nanomaterials are engineered and manipulated at the atomic and molecular level for specific properties and behaviours. They can be nanoparticles, nanotubes, nanofibers or nanocoatings, among others. Their nanometric size gives them different properties from their macroscopic counterparts. These are mainly:

• Small size: Nanomaterials are similar in size to biological structures and can interact at the cellular level, opening the door to applications in medicine and biotechnology.
• Enhanced properties: At the nanometre level, materials can exhibit enhanced properties, such as increased resistance, electrical conductivity, or light absorption capacity. This enables applications in electronics, renewable energy, and optics.
• Extended surface area and dispersion: Due to their high area-to-volume ratio, nanomaterials have an extended surface area that facilitates catalysis and adsorption of substances, thus making them useful in water purification, energy production and pollutant removal. In addition, due to their size, effective dispersion in a composite can enhance its properties while using small amounts of the nanomaterial.
• Quantum behaviour: At the nanoscale, materials can exhibit quantum behaviour, such as emitting light in specific colours. Applications in nano- and optoelectronics are based on these phenomena.

Reduced graphene oxide is obtained through several chemical processes using graphite, a crystalline form of carbon composed of layers of carbon atoms arranged in a hexagonal structure. 

Graphite is initially subjected to controlled oxidation, using chemical oxidising agents such as nitric acid and sulphuric acid. This oxidation breaks down the graphite layers and introduces oxygenated functional groups into the structure, generating a two-dimensional layered structure of graphene oxide.

After the graphene oxide is obtained, the next step is its reduction. The reduction of graphene oxide requires the partial removal of the oxygenated functional groups. This is achieved by controlled chemical and/or thermal processes. As a result, the graphene structure is partially restored, and the reduced graphene oxide is formed.

In terms of applications, rGO is a material very much like monolayer graphene. It therefore has very similar properties:

• Electrical conductivity: rGO has an excellent electrical conductivity. This makes it a highly promising material for use in electronic devices, such as transistors, sensors, and solar cells.
• Thermal conductivity: In addition to its electrical conductivity, rGO also shows high thermal conductivity. This is a valuable property for heat management applications such as heat sinks and thermally conductive coatings.
• Flexibility and mechanical resistance: Although rGO does not achieve the same mechanical resistance as pure graphene, it still maintains remarkable flexibility and resistance. This makes it suitable for use in composites as it can enhance the mechanical properties of the materials and increase their resistance.
• Transparency: rGO is transparent over a broad range of wavelengths, thus making it a promising candidate for applications in flexible displays, smart windows, and optoelectronic devices.
• Surface chemistry and functionalisation: With the presence of functional groups in rGO, the modification and functionalisation of its surface is possible. This paves the way for a wide range of applications in areas such as catalysis, gas adsorption and biofunctionalisation.

rGO is a material with fascinating and promising properties. Its high electrical and thermal conductivity, flexibility, transparency, and surface chemistry make it valuable in fields such as electronics, energy, materials engineering, and biotechnology. New opportunities and applications in modern science and technology continue to emerge from the research and development of rGO.

We have recently certified our new product, Reduced Graphene Oxide (rGO+), at the prestigious CSIC Carbon Institute. This achievement positions us as a market leader, thanks to its exceptional properties: 98% carbon purity and very high conductivity.

Our product has been fully developed in Spain through an R&D process with a truly sustainable approach, both from an energy and environmental standpoint, ensuring our leadership in the manufacturing of these products in Europe.