This study presents, for the first time, an innovative Jet Plasma-assisted technique for the green synthesis of TiO₂@Ag core–shell nanoparticles using chard leaf extract as a natural reducing and stabilizing agent. The Jet Plasma provides a highly energetic environment that accelerates nucleation and core–shell formation at low temperatures without toxic precursors. The synthesized nanoparticles exhibited uniform and stable structures, as confirmed by comprehensive characterization techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) spectroscopy, transmission electron microscopy (TEM), and zeta potential analysis. XRD patterns confirmed the crystalline anatase phase of TiO₂ alongside distinct metallic silver phases. TEM images revealed spherical nanoparticles with silver cores measuring 4.5–4.9 nm surrounded by TiO₂ shells of 9–13 nm thickness. Optical analysis showed a surface plasmon resonance peak at 404 nm and a TiO₂ bandgap of approximately 3.0 eV. The nanoparticles demonstrated good colloidal stability with a zeta potential of –13.5 mV and exhibited effective photocatalytic activity in the degradation of organic dyes. Antibacterial evaluation using the broth dilution method revealed potent inhibitory effects against Staphylococcus aureus and Escherichia coli, with inhibition observed at concentrations ranging from 125 to 1000 μg/mL. These findings highlight the potential of these nanostructures for sustainable water treatment and enhanced photocatalytic applications. Highlights
