DESIGN AND FABRICATION OF POLYANILINE-GRAFTED NANOCARBON MATERIAL FOR ENERGY HARVESTING APPLICATION

Abstract

Nowadays, the development of high-performance and low-cost electrocatalysts to serve as an alternative to noble metals such as platinum in the oxygen reduction reaction (ORR), which is a crucial factor in advancing sustainable energy devices. In this study, nanocarbon (NC) particles derived from aniline and polyaniline-grafted nanocarbon (PANI-g-NC) were synthesized through a combination of solution plasma processing and a thermal reflux system. Compared with traditional catalysts, these PANI-g-NC hybrids offer distinct advantages: they avoid the high expense and limited availability of noble metals, provide higher electrical conductivity than pristine polymers, and introduce redox-active nitrogen functionalities that conventional carbons often lack. The solution plasma method enables the direct formation of nitrogen-doped nanocarbons from liquid aniline without external templates, while the thermal reflux step ensures the efficient grafting of polyaniline chains onto the carbon surface. The obtained samples were characterized using advanced techniques including SEM, TEM, Raman spectroscopy, XRD, and cyclic voltammetry (CV). SEM and TEM images revealed that the nanocarbon particles exhibit a spherical morphology. The FTIR spectra showed characteristic peaks corresponding to N–H stretching, aromatic C=C stretching, C–N stretching in amine confirming the successful grafting of polyaniline onto the nanocarbon surface. XRD analysis identified distinct diffraction peaks associated with multiple crystalline phases: nanocarbon (C), tungsten oxide (WO₃) and metallic tungsten (W). Meanwhile, electrochemical measurements (Cyclic Voltammetry) indicated a gradual decrease in the cyclic voltammetry loop area with increasing PANI grafting time. This study demonstrates an effective strategy to integrate the high electrical conductivity of nanocarbon with the redox activity of polyaniline via solution plasma processing, providing a green, sustainable, and low-cost alternative to platinum-based catalysts for fuel cell applications. More importantly, the PANI-g-NC hybrids exhibit a distinctive electrochemical behavior compared to conventional nanocarbons or bare polyaniline. The synergistic combination of a conductive carbon backbone with redox-active nitrogen functionalities in PANI enables a hybrid charge-storage mechanism, simultaneously enhancing electron transport, proton accessibility, and catalytic site density. This dual contribution underlines the novelty of the present material design and its promising potential as an efficient and durable electrocatalyst.