From hazardous waste to High-Performance Electrodes: Upcycling discarded cigarette filters into N/S co-doped...

Waste cigarette filters are a primary source of solid waste pollution, primarily due to the non-biodegradability and the persistent leaching of toxic chemicals. The recycling and reuse of discarded cigarette filters are therefore critically significant for environmental protection and sustainable resource management. Herein, this study proposed an innovative approach to convert waste cigarette filters into freestanding electrode materials, and it requires no complex pre-treatment of the collected used cigarette filters. The N/S co-doped carbon nanofiber membranes were fabricated from waste cigarette filters via electrospinning, deacetylation, and carbonization. The as-prepared N/S co-doped carbon membrane exhibits a specific surface area of 385 m²·g^-1 at the carbonization temperature of 900 °C, and it presents the highest specific capacitance of 229F·g^-1 due to the synergistic effect of porosity and heteroatoms doping. The assembled symmetric flexible supercapacitor achieved an energy density of 24 Wh·kg^-1 at a power density of 2500 W·kg^-1, and it shows an impressive capacitance retention rate of 78.1 % after 10,000 cycles. The results indicate that converting waste cigarette filters into freestanding carbon membranes is a promising strategy for developing high-performance supercapacitor electrode materials.