This study reports the green synthesis of a multifunctional Ag/ZnO/Fe₃O₄ nanocomposite using Murraya koenigii fruit pods and Cissus quadrangularis stem extracts as natural reducing and stabilizing agents. The synthesized nanocomposite was characterized using XRD, FTIR, Raman spectroscopy, UV-Vis spectroscopy, SEM, TEM, DLS, zeta potential, and VSM analyses, confirming its crystalline structure, nanoscale morphology, and soft-ferromagnetic properties. Photocatalytic efficiency under visible light showed significant degradation of Congo Red (87.9%) and Methylene Blue (86.9%) within 120 min, following pseudo-first-order kinetics. Enhanced activity was attributed to efficient charge separation and reactive oxygen species generation through a plasmon-assisted Z-scheme mechanism. The catalyst also exhibited excellent magnetic recoverability and reusability over five cycles. Additionally, notable antibacterial activity against Pseudomonas aeruginosa and cytotoxicity toward A549 lung carcinoma cells were observed, demonstrating its potential for sustainable environmental remediation and biomedical applications.

Keywords: Green synthesis; Ag/ZnO/Fe₃O₄ nanocomposite; Visible-light photocatalysis; Wastewater treatment; Magnetic recovery; Dye degradation.