Every year, billions of cigarette butts are discarded worldwide, creating one of the most pervasive and persistent forms of environmental litter. Now, researchers have demonstrated that this problematic waste can be converted into advanced carbon materials capable of powering next generation energy storage devices.
In a new study published in Energy & Environmental Nanotechnology, scientists report a method to transform waste cigarette butts into nitrogen and oxygen co doped nanoporous biochar with exceptional performance as an electrode material for supercapacitors. Supercapacitors are energy storage devices known for rapid charging, long cycle life, and high power output, making them attractive for applications ranging from portable electronics to renewable energy systems.
Globally, more than eight million tons of cigarette butts are generated each year. These filters, composed primarily of cellulose acetate, degrade very slowly and can release toxic chemicals into soil and water. Finding sustainable and scalable ways to reuse this waste has been a long standing environmental challenge.
"Our work shows that cigarette butts are not just a pollution problem, but also a valuable carbon resource," said corresponding author Leichang Cao. "By converting them into functional porous carbon materials, we can address waste management while supporting clean energy technologies."
The research team developed a two step process that combines hydrothermal carbonization with chemical activation and controlled heat treatment. During this process, nitrogen and oxygen atoms are introduced into the carbon structure, while a hierarchical network of microscopic pores is formed. This architecture is critical for efficient energy storage, as it provides abundant sites for charge accumulation and rapid pathways for ion transport.
The optimized material, produced at an activation temperature of 700 degrees Celsius, exhibited an exceptionally high surface area of more than 2,100 square meters per gram. When tested as an electrode in aqueous supercapacitors, it achieved a specific capacitance of nearly 345 farads per gram. Even after 10,000 charge and discharge cycles at high current density, the material retained more than 95 percent of its original capacity.
"These results are remarkable for a carbon material derived entirely from waste," said co author Jinglai Zhang. "The combination of rich porosity and nitrogen and oxygen functional groups gives the electrode excellent conductivity, stability, and energy storage capability."
When assembled into a full symmetric supercapacitor device, the cigarette butt derived electrodes delivered an energy density of over 24 watt hours per kilogram along with high power density, demonstrating their potential for real world applications.
Beyond performance, the approach offers important environmental advantages. Cigarette butts are widely available, inexpensive, and currently costly to manage as waste. Converting them into high value energy materials could reduce environmental contamination while lowering the cost and carbon footprint of electrode production.
"This study highlights a circular solution where an environmental liability becomes a technological asset," Cao said. "It opens new possibilities for turning everyday waste into materials that support sustainable energy systems."
The researchers emphasize that further work is needed to evaluate large scale processing and long term environmental impacts. However, the findings provide a compelling example of how waste derived biochar materials can contribute to both pollution reduction and clean energy innovation.
As the demand for efficient and sustainable energy storage continues to grow, transforming discarded cigarette butts into high performance supercapacitor materials may offer an unexpected but powerful path forward.
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Journal reference: Wang J, Wei C, Hou H, Zhang F, Liu C, et al. 2026. N,O co-doped hierarchical nanoporous biochar derived from waste cigarette butts for high-performance energy-storage application. Energy & Environment Nexus 2: e001
https://www.maxapress.com/article/doi/10.48130/een-0025-0016
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About Energy & Environment Nexus :
Energy & Environment Nexus (e-ISSN 3070-0582) is an open-access journal publishing high-quality research on the interplay between energy systems and environmental sustainability, including renewable energy, carbon mitigation, and green technologies.
