Mechanistic investigation of the graphene functionalization using p-phenylenediamine and its application for supercapacitors

The p-phenylenediamine (PPD) modified GO/rGO composite materials were synthesized by a facile solution processing with two different routes: 'Reaction first then Reduction' and 'Reduction first then Reaction', which are referred to as GPPDH and GHPPD, respectively. The mechanism is investigated by a systematic study. GPPDH with the PPD molecules inserted into the space of graphene sheets demonstrated a loose and crumpled microstructure. For GHPPD, the graphene sheets were restacked and cross-linked through PPD molecules. The synthesized material of GPPDH with high specific capacitance and good electrochemical cycling stability was considered to be a promising electrode material for supercapacitors.287