Polyacrylonitrile (PAN) is a widely used precursor for activated carbon using KOH as the activation agent. In the present work, we prepared activated carbon with high BET surface (2241 m²/g) by optimizing the activation temperature and the dosage of KOH. On this basis, we obtained PAN-based activated carbon doped with copper. The preparation is through a three-step process: (1) the nucleophilic reaction between nitrile groups and hydroxylamine (NH₂OH), introducing multi amino and oximido groups in PAN; (2) complexation of Cu²⁺ with oximido groups on modified PAN, resulting in a dark green colored complex; (3) carbonization of the complex in the presence of KOH at high temperature. The present method of doping-in-precursor may provides more homogeneous blending of metal in carbon matrix than simple mixing of activated carbon and copper. The copper-doped activated carbon was characterized by XPS, FT-IR and SEM. The doped copper undergoes the Faradic reactions to produce pseudo-capacitance, thus improving the specific capacitance of activated carbon electrodes from 208.3 F/g to 289.7 F/g (0.5 A/g). Nevertheless, the cycle stability of copper-doped activated carbon was lower than that of pure activated carbon after several recharge cycles. This was probably caused by the irreversible Faradic reaction of doped copper.

Key words: polyacrylonitrile, chemical complexation method, copper-doping, activated carbon