Green Synthesis of Ag-Cu NPs using Black Eggplant Extract as the Reducing and Stabilizing Agents: Characterization and Energy Band Gap

Abstract The study successfully demonstrated an eco-friendly approach to synthesizing Ag, Cu nanoparticles, and Ag-Cu nanoparticle composites using Black eggplant extract as both a reducing and stabilizing agent, with calcination at 400°C. The research revealed distinct plasmonic properties through Surface Plasmon Resonance (SPR) bands observed at specific wavelengths: 400 nm for Ag, 524 nm for Cu, and dual bands at 406 nm (SPR1) and 600 nm (SPR2) for Ag-Cu nanoparticle composites. The energy gap values for Ag-Cu were identified at 1.8eV, 2.5eV, and 3.7eV. XRD analysis confirmed a polycrystalline structure with a face-centered cubic (FCC) phase pattern, while FE-SEM and EDX examinations revealed homogeneous morphology with Cu nanoparticles being larger than Ag nanoparticles. The Ag-Cu nanoparticle composite exhibited similar size and shape characteristics to Ag nanoparticles, with an average size of 46.5nm. These findings demonstrate the successful synthesis of discrete and stable nano-sized particles with superior plasmonic properties, suggesting potential applications in enhancing electron transfer efficiency in nano-sized metal surfaces and various sensing and detection applications.