One-pot synthesis of covalently functionalized reduced graphene oxide–polyaniline nanocomposite for supercapacitor applications

A high-performance reduced graphene oxide–polyaniline (RGO-PANI) electrode material was prepared through commercially viable, facile one-pot synthesis, applying famed diazotization chemistry and grafting strategy. In this work, 4-nitroaniline was utilized as a grafting substrate to bind reduced graphene oxide and polyaniline covalently to a highly stable and efficient supercapacitor electrode material. The chemical composition and structural analysis of covalently functionalized RGO-PANI nanocomposites were characterized by X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, UV–visible spectroscopy, and Fourier-transform infrared spectroscopy. The electrochemical behavior of the nanocomposites was analyzed through cyclic voltammetry, galvanostatic charge and discharge, and electrochemical impedance spectroscopy. The prepared nanocomposite shows a high specific capacitance of 490 F g⁻¹ in 1 M Na₂SO₄ with outstanding cyclic stability (10,000 cycles). The applied covalent functionalization through grafting strategy was the principal factor for both high specific capacitance and excellent cyclic stability.