This invention describes a low-temperature pyrolysis method to produce graphene-rich carbon materials using hexagonal metal oxides as templates. The process prevents graphene stacking into graphite and allows nitrogen doping, enhancing properties for applications like electrodes and catalysts.
Graphene, a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, has exceptional electrical, thermal, and mechanical properties. These characteristics make graphene a highly sought-after material for a wide range of applications, including electronics, energy storage, and composite materials. However, the challenge lies in producing graphene at a scale and cost that makes it viable for widespread industrial use.
Traditional methods of producing graphene, such as chemical vapor deposition and mechanical exfoliation, are often expensive, complex, and not easily scalable. As a result, there is a pressing need for more efficient and cost-effective methods to produce high-quality graphene materials that can meet the demands of various industries.
Current approaches to graphene production face several significant challenges. One of the primary issues is the tendency of graphene sheets to stack together, forming graphite, which diminishes their unique properties. This stacking occurs due to strong van der Waals forces between the sheets, making it difficult to maintain the single-layer structure necessary for optimal performance. Additionally, many existing methods require high temperatures and complex processes, which increase production costs and limit scalability. Furthermore, achieving specific properties, such as nitrogen doping, which can enhance the material’s functionality for certain applications, adds another layer of complexity.
These challenges highlight the need for innovative methods that can produce graphene with controlled properties, reduced stacking, and at lower temperatures, thereby making the material more accessible for commercial applications.
This technology describes a method for producing carbon materials that are rich in graphene sheets by using pyrolysis at temperatures below 800°C. The process employs hexagonal metal oxides as templates to prevent the stacking of graphene sheets, which would otherwise lead to graphite formation. This method ensures that the graphene sheets remain largely unstacked and allows for the incorporation of nitrogen into the graphene structure, resulting in heavily nitrogen-doped graphene.
The process involves heating a salt containing carbon, oxygen, and metal ions in an inert atmosphere to form graphene-rich carbon and a hexagonal metal oxide. The metal oxide is then removed using an acid treatment, leaving behind the graphene-rich carbon. This approach creates graphene materials with properties, such as high surface area and controlled nitrogen content, which can be useful in applications like electrodes, catalysts, and gas adsorption.
What differentiates this technology is its ability to produce graphene materials at relatively low temperatures, which prevents the extensive stacking of graphene sheets and maintains their unique properties. The use of hexagonal metal oxides as templates is a novel approach that helps in achieving this goal.
Additionally, the method allows for the incorporation of nitrogen into the graphene structure, enhancing its properties for specific applications. The resulting nitrogen-doped graphene has a high surface area and controlled nitrogen content, making it suitable for a wide range of applications, including energy storage, catalysis, and gas adsorption. This method provides a more efficient and cost-effective way to produce high-quality graphene materials compared to traditional methods that require higher temperatures and more complex processes.
https://patents.google.com/patent/US10968105B2/en?oq=10%2c968%2c105