C-doped g-C3N4@Polyaniline (PANI) Composites as High-Performance Electrode for Supercapacitor Applications

Graphitic carbon nitride (g-C3N4) is a promising supercapacitor electrode material owing to its layered structure and nitrogen-rich framework, but its limited conductivity and moderate specific capacitance restrict practical applications. This study reports C-doped g-C3N4@Polyaniline (PANI) composites for supercapacitor electrodes. Undoped g-C3N4 was synthesized via thermal polymerization of melamine at 550°C, while C-doped g-C3N4@PANI composites with PANI loadings (3.2, 6.3, and 9.1 wt%) were prepared by ultrasonic-assisted wet impregnation. X-ray diffraction confirmed the preserved g-C3N4 structure with peak shifts and broadening, indicating successful carbon doping and reduced crystallite size. Fourier Transform Infrared spectroscopy verified the chemical integrity of both components and revealed strong hydrogen bonding between g-C3N4 and PANI. Field Emission Scanning Electron Microscopy showed morphological evolution from flake-like sheets to PANI-coated structures. Electrochemical measurements showed the 3.2 wt% PANI composite achieving the highest specific capacitance of 45 F/g (CV) and 42 F/g (GCD), compared to 25 F/g (CV) and 23 F/g (GCD) for undoped g-C3N4, with reduced charge transfer resistance and improved ion diffusion. The synergistic combination of electric double-layer capacitance from g-C3N4 and pseudocapacitance from PANI positions these composites as promising electrode materials for next-generation supercapacitors.