From Waste to Watts: Cigarette Filter Waste to Carbon Nanomaterial‐Based Supercapacitors for Sustainable Energy Storage Applications

ABSTRACT Currently, the rapidly growing population is producing hazardous waste materials at an unprecedented rate, which seriously affects the global environment. Additionally, increasing population and pollution have amplified the need for renewable energy and efficient energy‐storage technologies. One strategy is to implement greener processes for efficiency and/or utilize the waste generated for useful domestic and industrial applications. In this context, here, we harnessed the most littered environmental pollutant, cigarette filter waste (CFW), to synthesize carbon nanomaterials (CNM) via a single‐step pyrolysis process, devoid of any catalyst or activating agent, possessing optimal characteristics for serving as an active electrode material in the fabrication of cutting‐edge supercapacitors, thereby addressing the issue of waste recycling and the need for energy storage devices among the populace. Supercapacitors, namely SC‐1 to SC‐4 matching electrolytes, 1M H 2 SO 4 , 2M H 2 SO 4 , 1M KOH, and 2M KOH, fabricated using CNM electrodes were evaluated. Among these, SC‐2 exhibits superior performance, demonstrating a remarkable capacitance of 240 Fg –1 at low scan rates (2 mVs –1 ), an enhanced energy density (22.4 Whkg –1 ), and commendable power density (399.43 Wkg –1 ). Furthermore, SC‐2 maintained 5000 cycles of outstanding stability with 97.8% capacitance retention. This study unveils the potential of CFW‐derived CNMs as an electrode material for the realization of state‐of‐the‐art supercapacitors.