Green synthesis of silver nanoparticles using Solanum melongena peel and Abelmoschus esculentus extracts: a dual study on antibacterial efficacy and photocatalytic activity

In this research, silver nanoparticles (Ag-NPs) were created using Solanum melongena peel and Abelmoschus esculentus extracts through a green method. The techniques of UV–Vis, XRD, TEM, FESEM/EDX, and FTIR were employed to characterize the crystalline phase, morphology, and functional groups of NPs. The UV–Vis analysis revealed the effective formation of Ag-NPs by a characteristic Surface Plasmon Resonance (SPR) peak at 450 nm. The XRD pattern of Ag-NPs showed a crystalline structure with a mean crystallite size of 17 nm. TEM and FESEM images showed spherical morphology with average particle diameters of 21.95 nm and 53.63 nm, respectively. Additionally, FTIR spectroscopy demonstrated the participation of phytochemicals from the plant extracts in nanoparticle formation and stabilization. The photodegradation performance of the nanoparticles has been assessed for the decolorization of methylene blue (MB) pigment under ultraviolet A (UVA) irradiation. The nanoparticles exhibited high photocatalytic efficiency, achieving 93.35% degradation of MB within 90 min, following pseudo-first-order kinetics. The biosynthesized Ag-NPs also exhibited potent antimicrobial efficacy toward disease-causing bacteria associated with humans, with inhibition zones ranging from 11 to 20 mm at a concentration of 1 mg/mL. The novelty lies in the synergistic dual-extract system, where Solanum melongena provides high reducing power and Abelmoschus esculentus mucilage acts as a superior capping agent, yielding highly stable, small-sized Ag-NPs with enhanced antibacterial and photocatalytic performance.