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Description
Silver nanoparticles (AgNPs) have attracted considerable attention as catalysts due to their high surface reactivity, yet their tendency to aggregate limits reusability and long-term performance. In this study, calcined eggshells—a low-cost, calcium-rich waste material—were employed as a support matrix to stabilize AgNPs synthesized via the polyol method, using polyvinylpyrrolidone (PVP) as a capping agent and ethylene glycol as both solvent and reducing agent. AgNPs were prepared at four AgNO3 precursor concentrations (12.5, 25, 37.5, and 50 mM) to evaluate the effect of precursor loading on particle formation and catalytic activity. The resulting composites were characterized using UV-Vis spectroscopy to confirm surface plasmon resonance at 400-450 nm, FTIR to identify functional groups involved in nanoparticle stabilization, XRD to determine crystallinity and phase composition, and SEM to observe surface morphology and particle distribution on the eggshell support. Catalytic performance was evaluated through the reduction of Rhodamine B (RhB), a model organic dye pollutant, in the presence of a reducing agent (NaBH4). Results demonstrate that AgNO3 concentration significantly influences nanoparticle size, distribution, and dispersion on the support, which in turn affects catalytic efficiency that was completed within 14-18 minutes. This work highlights the potential of biogenic waste-derived materials as sustainable supports for metal nanoparticle catalysts in environmental remediation applications.
Keywords: silver nanoparticles, calcined eggshell, polyol, rhodamine B, catalysis
