Phosphazene-Based Covalent Organic Polymer/Bismuth Ferrite/Polyaniline Nanocomposites as a Supercapacitor Electrode Material for Red LED Powering

Covalent organic frameworks (COFs) have garnered considerable attention as supercapacitor electrode materials due to their large specific surface area and adjustable pore structure, but they are practically limited by poor conductivity. To address this limitation, in this study, we developed a nanocomposite material (P-COP/BiFeO3/PANI) using the phosphazene-based covalent organic polymer (P-COP), bismuth ferrite (BiFeO3), and polyaniline (PANI) through the in situ polymerization of aniline via the solvothermal method. P-COP, BiFeO3, and PANI were synthesized individually through the condensation reaction, the sol–gel method, and oxidative polymerization, respectively, for comparative electrochemical performance. The developed nanocomposite material was extensively characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), Brunauer–Emmett–Teller (BET), and X-ray photoelectron spectroscopy (XPS). To assess the electrode’s electrochemical performance of the nanocomposite electrode material (P-COP/BiFeO3/PANI), cyclic voltammetry (CV), galvanic charge–discharge (GCD), and EIS measurements were studied. To investigate the capacitive and diffusive contributions in the devices, CV curves were further investigated for our developed nanocomposite electrode material at 100 mV s–1. The diffusive contribution is 46%, reaching up to 28% at 5 mV s–1. Conversely, the device’s capacitive contribution is 53% at a lower scan rate of 5 mV s–1 to 73.1% at 100 mV s–1. At a current density of 2 A g–1, the P-COP/BiFeO3/PANI nanocomposite material exhibited a specific capacitance of 585 F g–1, outperforming both pure P-COP and the P-COP/BiFeO3 composite. Furthermore, this nanocomposite has good cyclic stability, maintaining around 88.46% of its specific capacitance for up to 3000 cycles. The electrochemical response was remarkable, confirming that the P-COP/BiFeO3/PANI nanocomposite is a promising electrode material for supercapacitors and practical application using red LEDs, paving the way toward the futuristic development of energy storage devices.