Waste toner derived Fe₃O₄ nanoparticles embedment into PANI matrix as an advanced electrode for supercapacitor

Abstract The advancement in materials for energy storage devices that exhibit excellent energy and power density with prolonged cyclic stability are crucial for resolving energy crises. This research work demonstrates the embedment of Fe 3 O 4 nanoparticles into the polyaniline matrix with improved electrochemical performance and good retention capacity. Herein, the Fe 3 O 4 nanoparticles have been derived from waste toner powder, effectively reduce environmental pollution by repurposing a harmful waste product. The PANI/Fe 3 O 4 based electrode with an optimised ratio exhibits the specific capacitance of 831 F.g −1 at a current density of 1 mA cm −2 in 3 M KOH electrolyte using three electrode configuration with commendable retention capacity. Additionally, the PANI/Fe 3 O 4 electrode ultimately demonstrates the energy density of 166.2 W.h.kg −1 and power density of 5.0 kW.kg −1 at the high current density of 5 mA cm −2 in 1 M concentration of KOH electrolyte. Eventually, the PANI/Fe 3 O 4 based electrode exhibits a specific capacitance of 103.5 F g −1 at a current density of 1 mA cm −2 , when used as cathode in two-electrode configuration.