Sustainable Nanocomposite Fabrication from Pistachio Shells and Aluminum Cans: Alumina-Activated Carbon with Silver Ferrite Nanoparticles for High-Performance Supercapacitors

Recently, the valorization of agricultural and industrial wastes has gained significant attention for the synthesis of high-value nanomaterials. In this study, we investigate the synthesis and characterization of composite materials comprising activated carbon (AC) derived from pistachio shells, alumina nanoparticles (Al₂O₃) sourced from recycled aluminum cans, and silver ferrite nanoparticles (AgFeO₂) for potential energy storage applications. The nanocomposites were characterized using XPS, FTIR, BET, SEM, TEM, and EDX techniques to analyze their structural, chemical, and morphological properties. XPS analysis revealed the oxidation states and chemical interactions between the components, confirming the successful integration of AgFeO₂ into the AC and alumina matrix. FTIR spectra indicated the presence of hydroxyl, carbonyl, and ferrite functional groups. Textural analysis demonstrated that the composites possessed a hybrid microporous-mesoporous structure, with significant surface area retention and optimized pore sizes. TEM and SEM imaging showed uniform nanoparticle dispersion, highlighting the composites’ high structural integrity. Electrochemical evaluation indicated superior capacitive performance, with the 10 wt% AgFeO₂-Alum-AC composite achieving the highest specific capacitance (480 F/g at 0.7 A/g) and excellent cycling stability. These findings establish the AgFeO₂-modified Alum-AC composite as a viable material for high-performance supercapacitors.