Graphene oxide (GO) is a derivative of graphite formed during the conversion of graphite into graphene. It is typically produced by oxidizing graphite, followed by exfoliation, dispersion, and size reduction to obtain sheet-like materials. Graphene oxide was first reported by Oxford University chemist Benjamin Brodie in 1859.
Graphene oxide is a two-dimensional nanomaterial that can consist of a single atomic layer. Its structure contains carbon atoms with both sp² and sp³ hybridization, along with various oxygen-containing hydrophilic functional groups, including hydroxyl, carboxyl, and epoxy groups. These functional groups contribute to its good dispersibility in aqueous media.
Common preparation methods for graphene oxide and related graphene materials include oxidation, solvent-assisted exfoliation, chemical vapor deposition (CVD), micromechanical exfoliation, and epitaxial growth on metal surfaces. Among these methods, oxidation is widely used for graphene oxide production because it is relatively simple, cost-effective, and suitable for large-scale manufacturing. Common oxidation methods include the Staudenmaier, Brodie, Hummers, and Offeman methods.
Due to its relatively low production cost, good film-forming properties, high specific surface area, and ease of functionalization, graphene oxide has broad application potential in energy storage, batteries, photocatalysis, biomedical research, sensors, and water treatment. It is also used as a functional additive or modifier in polymer foams, including polystyrene (PS), polypropylene (PP), polyurethane (PU), polylactic acid (PLA), and poly(methyl methacrylate) (PMMA).
| Parameter | Specification |
|---|---|
| Sheet Size | 0.5–5 μm |
| Thickness | 0.8–1.2 nm |
| Purity | Approximately 99% (by EDS analysis) |
1. Single-Layer Structure
This single-layer graphene oxide powder from Xianfeng Nano is prepared using a modified Hummers method, followed by freeze-drying to obtain a powder product. Due to surface corrugation associated with maintaining thermodynamic stability, the average sheet thickness is 0.8–1.2 nm. The reported single-layer content is 99%.
2. Good Dispersibility
Oxygen-containing functional groups on the surface contribute to good dispersibility in water and polar organic solvents, facilitating incorporation into a variety of material systems.
3. Easy Functionalization
The surface contains various oxygen-containing functional groups, including hydroxyl, carboxyl, and epoxy groups. These groups can be modified through chemical reactions to introduce additional functionalities and tailor the properties of graphene oxide for specific applications.
4. Abundant Active Sites
The preparation process introduces numerous chemically active sites that can interact with other substances, supporting surface modification, composite formation, and related material research.
5. Distinctive Optical Properties
Graphene oxide exhibits absorption in the visible-light region. Its optical properties can be adjusted by modifying its structure, degree of oxidation, and surface functional groups.
6. Tunable Electrical Properties
Graphene oxide is generally electrically insulating because of the disruption of its conjugated carbon network by oxidation. Reduction can partially restore the conjugated structure and recover electrical conductivity. Its electrical properties can also be tailored through doping and other modification strategies.
1. Electronic Devices and Sensors
Graphene oxide can serve as a functional component or precursor material in the development of electronic devices. Reduced graphene oxide (rGO)-based field-effect transistors have been investigated for chemical and biological sensing applications. Its surface functional groups also support the modification of sensor interfaces.
2. Energy Storage
Reduced graphene oxide-based nanocomposites have been investigated for high-capacity energy storage in lithium-ion batteries. Due to their large accessible surface area and tunable structure, reduced graphene oxide materials are also studied as electrode materials for supercapacitors.
3. Biomedical Research and Drug Delivery
Graphene oxide has been investigated as a component of drug delivery systems. Functionalized graphene oxide nanomaterials can be designed to carry therapeutic compounds and have been studied for targeted delivery of anticancer agents. Their suitability depends on surface chemistry, formulation, biocompatibility, and other application-specific factors.
4. Biosensors
Graphene oxide can act as a fluorescence-quenching material in biosensors based on fluorescence resonance energy transfer (FRET). Its interactions with fluorescent probes and biomolecular targets can support the development of sensing platforms for biological analysis.
5. Environmental Protection
Graphene oxide-based composites have been investigated for environmental applications, including the capture or treatment of certain hazardous gases and the removal of pollutants from water and air. Depending on the composite design, some systems may also support the conversion of selected pollutants into useful chemical products or energy-related resources.
