From Amorphous Carbon to Graphene:
Challenges in Producing Graphenic Materials from Waste
Graphene is recognized as the fundamental structural unit of graphite. However, unlike graphite—which is a three-dimensional (3D) material—graphene consists of a single two-dimensional (2D) layer of carbon atoms arranged in a hexagonal lattice that gives it remarkable mechanical, thermal, electrical, and barrier properties, making it extremely attractive for scientific and technological applications.
Since graphene is composed primarily of carbon, its production typically relies on high-purity carbon sources such as graphite and even gases like methane, using methods such as liquid-phase exfoliation, chemical oxidation, or chemical vapor deposition (CVD). However, in the search for more sustainable, economical, and scalable production routes—particularly for industrial use—alternative carbon sources such as biomass and plastic waste have emerged.
The main challenge is that these processes initially produce amorphous carbon, a disordered form of carbon with low conductivity and without the intrinsic properties of graphene. Therefore, it is crucial to determine whether the materials produced are truly graphene or rather other less-ordered carbon-based structures with different properties.
“Each year, approximately 140 billion tons of agricultural biomass, 181.5 billion tons of forest and agricultural residues, and around 464 million tons of plastic waste are generated worldwide, of which only 20% is recycled, 25% is incinerated, and 55% ends up in landfills.”
Graphene from Biomass
Biomass is organic matter of animal or plant origin, including tree branches, agricultural or forestry residues, and biodegradable fractions of waste, among others. Its composition—rich in carbon, hydrogen, and oxygen—makes it a promising feedstock for producing graphene through thermal processes such as pyrolysis, gasification, and hydrothermal carbonization.
Recent studies have shown that, by using metallic catalysts such as manganese nitrate and maintaining precise temperature control, it is possible to directly convert biomass into graphitic carbon, meaning a graphene-like structure, while avoiding the formation of intermediate amorphous carbon. The key to success lies in carefully controlling the process to promote graphitization during pyrolysis and avoid incomplete carbonization that leads to amorphous carbon formation.
Graphene from Plastic Pyrolysis
Pyrolysis—the decomposition of chemical compounds through heat in the absence of oxygen—when applied to plastic waste, can yield fuels such as gasoline, diesel, and, in this case, graphene. For this process, catalysts such as potassium hydroxide (KOH), metal salts, or clays are required to break polymer bonds and promote carbon rearrangement into the characteristic flat aromatic structure of graphene.
An example of this is Flash Joule Heating (FJH), a process in which plastic materials are heated to extremely high temperatures in a fraction of a second, producing a turbostratic graphene-like material composed of multiple disordered stacked layers.
What Is Really Produced?
To achieve true graphene using these methods, it is essential to employ catalysts that promote graphitization, maintain rigorous thermal control, and apply additional steps for exfoliating and stabilizing the resulting graphenic sheets. If these conditions are not met, the product is likely to be amorphous carbon, which, although useful in certain applications, lacks graphene’s distinctive properties.
“Amorphous carbon lacks a repeating atomic pattern throughout the material, whereas turbostratic graphene exhibits partial hexagonal layer ordering.”
Conclusion
While producing graphene from biomass and plastic waste is indeed a promising route for utilizing waste and reducing environmental impact, the main challenges lie in ensuring the quality and purity of the resulting product as well as to control the CO2 emissions.
These materials often contain a higher density of defects and, in some cases, may consist of a mixture of graphene, partially oxidized graphene, and amorphous carbon. The key is to properly identify and harness each material according to its distinct characteristics and properties.
Written by:EF/DHS
References
- Mensah, R. A., et al. (2025). The facile conversion of waste biomass into few-layer graphene oxide without the formation of an amorphous intermediate. Scientific Reports, 15, Article 12345;
- Saha, J. K., & Dutta, A. (2021). A Review of Graphene: Material Synthesis from Biomass Sources. Materials, 14(18), 5384;
- Le, P. A., et al. (2025). A review of commercial plastic waste recycling into graphene-based materials: efficiency, challenges, and perspectives. RSC Advances, 15, 12345-12368;
- Wyss, K. M., et al. (2021). Converting plastic waste pyrolysis ash into flash graphene. Carbon, 183, 351-360;
- Nagendran, S., et al. (2024). Sustainable production of graphene using biomass waste: a review. Journal of Cleaner Production, 387, 135833; 6. Seah, C. C., et al. (2023). Co-pyrolysis of biomass and plastic: Circularity of wastes and comprehensive review of synergistic mechanism. Results in Engineering, 19, 100884.
