Preparation of novel pigskin-derived carbon sheets and their low-temperature activation-induced high capacitive performance

Abstract

Nitrogen- and oxygen-doped carbon sheets are prepared by the carbonization and KOH-activation of collagen-rich biomass resource pigskin and employed as supercapacitor electrodes. The porosity and surface chemistry are tailored by controlling the activation temperature from 600 to 900 °C, and the specific surface area and nitrogen content vary between 2209 and 3337 m² g⁻¹ and between 0.65 and 3.77 wt%, respectively. Considerable oxygen content ranging from 8.39 to 12.28 at% is also attained. The sample activated at 600 °C exhibits an exceptional specific capacitance of up to 547 F g⁻¹ in 6 M KOH due to abundant effective micropores and high heteroatom content, which induce high double-layer capacitance and additional pseudocapacitance, respectively. Furthermore, pigskin-derived carbon shows excellent high rate performance with a specific capacitance of 278 F g⁻¹ at 10 A g⁻¹ and 224 F g⁻¹ at 50 A g⁻¹ and good cycling stability (93% retention at 2 A g⁻¹ after 10 000 cycles).