Green Synthesis of Fe ₃ O ₄ Nanoparticles Using Tea Leaf Extract for Polyacrylamide Adsorption

Magnetic Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs) were synthesized via a green method using Camellia sinensis leaf extract as a reducing and stabilizing agent. The obtained superparamagnetic nanoparticles exhibited a saturation magnetization of ∼50 emu/g and an average crystallite size of ∼20 nm, formed at 180°C over 8 h. These nanoparticles were applied as adsorbents for polyacrylamide (PAM) removal from aqueous solutions. Adsorption followed a pseudo‐second‐order kinetic model and fitted the Langmuir isotherm, with optimal conditions at pH 8, 50 min contact time, and 1.5 g/L dosage, achieving 99% removal efficiency. The Fe 3 O 4 NPs were easily recovered using an external magnetic field, highlighting their potential as low‐cost, eco‐friendly, and reusable adsorbents for water treatment applications.