Removal of methylene blue using biosynthesized silver nanoparticles

Document Type: Original Research Paper


Department of Chemistry, Arak Branch, Islamic Azad University, Arak, Iran



In recent decades, the focus of science and industry has been concentrated on production of metal nanoparticles (NPs). In this study, the biosynthesis of silver NPs by using Tragopogon buphthalmoides (Tragopogon b.) plant was investigated. Various effective parameter on the synthesis such as pH, extract volume, concentration of silver nitrate, temperature and reaction time were optimized. Silver nanoparticles were synthesized under optimal conditions of 0.5 mL Tragopogon b. extract, 4.5 mM silver nitrate, pH=10, temperature=70 °C and synthesis time of 180 min. Characterization of synthesized NPs performed at optimal condition by using UV-Vis spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FT-IR). Also study of first and second-order kinetic to adsorption process of methylene blue by synthesized NPs at the optimal condition was performed. Resulted absorption peaks, indicated strong peaks around the λ = 420 nm which is the certain wavelength for silver NPs. TEM studies indicated that the silver NPs are spherical with average diameter of 13 nm. In adsorption kinetic studies was find out that, the adsorption process follows the second-order kinetic model (R2 = 0.9977, qe = 21.79 mg/g) . The results of present study showed that the plants well play role in reducing and stabilizing the metal NPs, due to their antioxidant properties and high secondary constituents and have high potential to synthesis of metal NPs which can be used in removal of dye contaminants.