Green fabrication of iron oxide nanoparticles from Lantana camara leaf extract for degradation of methylene blue dye

Aim: This study explores the green synthesis of iron oxide nanoparticles from the leaf extract of Lantana camara in order to test their efficacy for degradation of methylene blue dye. Methodology: Lantana camara leaves were collected, washed, dried, crushed to fine powder, and dissolved in different amounts (1g, 5g, 10g and 15g) in distilled water. For nanoparticle synthesis, ferric chloride and NaOH were added to the extract in different ratios, yielding optimal precipitation in 1:1 ratio with 10 g of extract. Bulk synthesis was conducted, followed by magnetic stirring to observe color change and precipitation. The prepared nanoparticles were applied to dye degradation studies inorder to assess the pH, concentration, effects of dosage, and contact time on methylene blue degradation efficiency and kinetic studies. Results: Adsorption followed pseudo-first-order kinetics, with removal efficiency of 85% at pH 12 and 550 mg l-1 dye concentration, showing a maximum removal efficiency at a contact time of 180 min. Interpretation: The findings suggest that green-synthesized iron oxide nanoparticles offer a sustainable, cost-effective alternative to conventional adsorbents for wastewater treatment, with the potential for reuse after regeneration.