Graphene oxide (GO) and reduced graphene oxide (rGO) are two of the most prominent types of graphene, both with varying properties for various applications. Both are processed from graphite, but their chemical processing and structural differences make them have varying properties as far as electricity, strength, and chemistry are concerned.
Graphene and Its Derivatives
Graphite is a natural carbon material composed of layers of carbon atoms in a hexagonal arrangement. It is graphene when such layers are reduced, an extremely thin layer of carbon one atom thick. Graphene possesses excellent electrical, thermal, and mechanical qualities. Yet, producing large quantities of pure graphene remains a challenge and expensive, and therefore the market is considering graphene oxide (GO) and reduced graphene oxide (rGO) as more accessible alternatives.
Graphene Oxide (GO)
Graphene oxide is an oxidized form of graphene. It is typically prepared by top-down means, i.e., Hummers’ method. The process involves inserting oxygen groups, i.e., hydroxyl, epoxy, and carboxyl, onto the planar surface and edges of graphene sheets. The changes break the sp² network of bonds and significantly alter its properties.
Graphene Oxide Specification
Purity: ~99% – Particle Size D50: <10 µm – Thickness: 0.8–2 nm – C:O Ratio: ~55:45 – Bulk Density: 0.8–1 g/cm³ – Physical Form: Powder – Colour: Yellow-Brown – Surface Area: ~120 m²/g – CAS No.: 1034343-98-0
Key Properties of GO:
- Low electrical conductivity
- Hydrophilic and easily dispersible in water and some organic solvents
- Good mechanical strength
- Surface functional groups allow easy chemical modification
Applications of GO
- Used to enhance the characteristics of concrete
- Used for water desalination
- Used in flexible electronics
- Used to make anti-barrier coatings
- Used for chemical sensors
- Very minute quantity can improve properties of polymers
- Used to improve the properties of elastomers
- Small quantity of GO can improve the properties of paints & coatings
Reduced Graphene Oxide (rGO)
Reduced graphene oxide is formed by removing some of the oxygen-containing groups from GO via thermal, chemical, or photothermal methods. While rGO doesn’t reach the perfection of pristine graphene, it recovers a significant portion of graphene’s electrical and mechanical properties.
Reduced Graphene Oxide Specification
Purity: ~99% – Thickness: ~0.8–2 nm – C:O Ratio: ~90:10 – Bulk Density: 0.014 g/cm³ – Physical Form: Fluffy Powder – Colour: Black – Surface Area: ~400 m²/g – CAS No.: 1034343-98-0
Key Properties of rGO:
- High electrical conductivity
- Hydrophobic in nature
- Lower dispersibility in aqueous media compared to GO
- High mechanical strength
Applications of rGO
- Electrodes for supercapacitors
- Conductive components in printed electronics
- Small quantity used to make anti-corrosion coatings
- Used to improve the properties of polymer
- Improve power and energy density and extend battery cycle life
- Used to make chemical sensors
- Used to make anti-barrier coatings
- Very minute quantity can improve properties of concrete
- Used to make RFID coatings
Graphene Oxide vs. Reduced Graphene Oxide: Key Differences
| Property | Graphene Oxide (GO) | Reduced Graphene Oxide (rGO) |
| C:O Ratio | ~55:45 | ~90:10 |
| Electrical Conductivity | Insulating to semi-conductive | Highly conductive |
| Surface Area | ~120 m²/g | ~400 m²/g |
| Bulk Density | 0.8–1 g/cm³ | 0.014 g/cm³ |
| Hydrophilicity | Hydrophilic | Hydrophobic |
| Dispersibility | Excellent in water | Lower in water |
| Mechanical Strength | Moderate | Very high |
| Colour | Yellow-brown | Black |
Conclusion
Graphene oxide and reduced graphene oxide both possess unique strengths due to their chemical composition and physical characteristics. GO is best for compatibility with other materials and is highly reactive, making it ideal for functional coatings, membranes, and biomedical carriers. rGO is more conductive and has greater tensile strength, however, and is ideal for energy storage, electronics, and high-performance materials.
At Adnano Technologies, we Manufacture high quality GO and rGO materials for research and industrial applications. If you are developing new applications, you should understand the difference between the two materials so that you can choose the most appropriate material for your project.