Transforming Disposed Face Masks into S‐Doped Carbon Nanofibers for High Performance Supercapacitors

Abstract

The substantial increase in discarded face masks since the onset of the COVID‐19 pandemic has resulted in extensive environmental pollution from plastic waste. This study presents a novel upcycling method to repurpose disposable face masks into a carbon‐based nanomaterial for use in supercapacitors. The upcycled sample, CSDFM@800, demonstrates very good supercapacitor properties, boasting a high specific capacitance of 234 F g⁻¹ at a current density of 0.5 A g⁻¹. Additionally, the symmetric coin cell supercapacitor constructed from this material exhibits excellent performance, achieving a high energy density of 8.54 Wh kg⁻¹ at a low current density of 0.5 A g⁻¹, and maintaining superior capacitance retention of 96.8 % after 15,000 charge/discharge cycles at a current density of 10 A g⁻¹. Materials characterisation results and electrochemical analysis reveal that this upcycling process not only preserves the carbon nanofiber structure but also introduces highly reactive sulfur as a heteroatom doping element.