N-doped porous carbon derived from rGO-Incorporated polyphenylenediamine composites for CO₂ adsorption and supercapacitors

A novel hierarchical porous carbon derived from poly(p-phenylenediamine) incorporated with reduced graphene oxide (rGO) is prepared for CO₂ capture and supercapacitors. In this synthesis, chemically in-situ oxidative polymerization and KOH chemical activation are employed with the controllable introduction of GO (GO/Polyphenylenediamine = 0–2 wt%). The obtained carbon material (APG-1%) with high surface area (860.4 m² g⁻¹) and rich N content (7.91 wt%) exhibits excellent CO₂ capture ability (4.65 mmol g⁻¹ at 298 K, 5 bar) and good electrochemical performance as a supercapacitor electrode with 158.5 F g⁻¹ in 6 M KOH at a current density of 1 A g⁻¹. Even at a high current density of 10 A g⁻¹, a capacity of 115.2 F g⁻¹ is still maintained. The rational addition of rGO provides an effective strategy of simultaneous improvement of CO₂ adsorption and capacitive performance.