Upcycling of Waste PVC into CaCO/KOH-Modified Porous Carbon for Supercapacitor Applications.

This study introduces a green method for converting waste polyvinyl chloride (PVC) into hierarchical porous carbon materials. By using CaCO pre-activation to capture HCl and form meso/macroporous frameworks, followed by KOH activation to tune microporosity, high-surface-area porous carbon was successfully produced. The effects of KOH loading ratios (C-PVC:KOH = 1:1 to 1:3) on the primary activated carbon material were systematically investigated. It was found that a ratio of 1:2 (C-KOH-2) yielded optimal material properties, with a specific surface area of 1729 m g and an oxygen doping content of 7.37%. Electrochemical measurements revealed that C-KOH-2 exhibited a high specific capacitance of 360.4 F g at 1 A g, retaining 72.1% of its capacitance at 10 A g. The symmetric supercapacitors achieved an energy density of 9.9 Wh kg at 125 W kg, with 93.12% capacitance retention over 5000 cycles. This dual-purpose approach enables the upcycling of PVC waste while promoting the development of high-performance electrodes.