Synergistic effect of bio-inorganic interface engineering and redox-active components in chitosan-Ag₂MoO₄-AgBr/RGO...

The development of sustainable and high-performance electrode materials is critical for advancing next-generation energy storage systems. Chitosan (CS), a renewable biopolymer, provides an eco-friendly platform for fabricating bio-inorganic hybrid electrodes with enhanced electrochemical performance. Owing to its biodegradable and bioactive nature, CS offers intrinsic environmental safety while enabling potential multifunctional applications such as antimicrobial coatings, biosensing, and water treatment in addition to energy storage. In this study, a series of nanohybrid composites pristine Ag₂MoO₄ (AgMo), CS-Ag₂MoO₄ (CS-AgMo), CS-Ag₂MoO₄-AgBr (CS-AgMo-AgBr), and CS-Ag₂MoO₄-AgBr-reduced graphene oxide (CS-AgMo-AgBr/RGO) were synthesized via a facile, solution-based method and systematically evaluated as electrode materials for supercapacitor applications. The synergistic integration of redox-active Ag₂MoO₄, faradaic AgBr, conductive RGO, and ion-permeable CS was explored to enhance charge storage capabilities. Electrochemical characterization in a three-electrode system revealed that the quaternary composite (CS-AgMo-AgBr/RGO) exhibited the highest specific capacitance of 724.02 F/g at 2 A/g, markedly outperforming pristine AgMo (419.73 F/g), CS-AgMo (588.35 F/g), and CS-AgMo-AgBr (656.58 F/g). This improvement is attributed to superior electron transport, enhanced redox activity, and better dispersion of active materials. Furthermore, a symmetric solid-state device based on the quaternary composite delivered an energy density of 47.50 Wh/Kg at a power density of 750 W/Kg and retained 84 % of its initial capacitance with a coulombic efficiency of 96 % after 20,000 charge-discharge cycles. These findings highlight the potential of bio-inorganic nanohybrids incorporating CS, AgBr, and RGO as high-performance, environmentally sustainable electrode materials. The CS-AgMo-AgBr/RGO composite emerges as a promising candidate for the development of next-generation, eco-friendly supercapacitor devices.