p-Phenylenediamine Functionalization Induced 3D Microstructure Formation of Reduced Graphene Oxide for the Improved Electrical double Layer Capacitance in Organic Electrolyte

Reduced graphene oxide (RGO) have been regarded as promising electrode material for supercapacitors. However, restacking of layers limits its surface area and pore volume which, in turn, suppress the electrochemical performances. Herein, we functionalize RGO with para-phenylenediamine (p-PDA) to suppress the problem and thus preserve the surface area and pore volume. p-PDA functionalized RGO (p-PDA-RGO) is explored as electrode materials for organic electrolytes based supercapacitors. The structural characteristics are characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and FT-IR. Electron microscopy demonstrates formation of randomly oriented 3D structure after functionalization. Effect of p-PDA functionalization toward surface area and pore volume is analyzed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analysis. The effect of p-PDA functionalization toward electrochemical performances is evaluated in symmetrical supercapacitors in organic electrolytes. p-PDA-RGO shows an improvement in capacitance over 10,000 cycles while attaining stability with high power capability.