Tuning the ionic conductivity of pectin biopolymer film via sodium azide reinforcement for possible electrochemical applications

This study presents the synthesis of a pectin biopolymer through an acidic extraction process from natural sources and the development of a conducting electrolyte film with enhanced conductivity via sodium azide reinforcement into it. The pure and modified self-standing polymer films were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and polarized optical microscopy (POM). XRD analysis confirmed proper phase formation and revealed a monotonic reduction in polymer crystallinity with increasing salt content, which was further supported by POM micrographs. FTIR analysis verified the presence of organic functional groups, showing no significant changes in vibrational energy levels upon salt incorporation. Electrochemical characterization using cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy demonstrated that the strong interaction between sodium azide and the pectin biopolymer significantly enhanced ionic conductivity and stability. It has been shown that upon optimized salt incorporation conductivity of the polymer got enhanced almost four orders. These findings underscore the potential of sodium azide-reinforced pectin films as a viable material for advanced energy storage and conversion devices, offering a promising pathway for future applications in electrochemical systems.