Facile Synthesis of Mordenite Nanoparticles for Efficient Removal of Pb(II) Ions from Aqueous Media

The current research presents the fabrication of mordenite nanoparticles via a hydrothermal technique using low-cost mixed organic templates. The utilized templates such as (polyethylene glycol 200 and glycerol), (polyethylene glycol 200 and ethylene glycol), (ethylene glycol and glycerol), and (ethylene glycol, polyethylene glycol 200, and glycerol) were named PEG-GL, PEG-EG, EG-GL, and EG-PEG-Gl, respectively. Characterization of the fabricated nanoparticles was carried using FE-SEM, HR-TEM, FT-IR, XRD, and BET techniques. XRD confirmed that the average crystallite sizes of PEG-GL, PEG-EG, EG-GL, and EG-PEG-Gl were 86.78, 38.75, 98.70, and 45.96, respectively. Also, HR-TEM confirmed that the average diameters of the previous samples were 80.42, 35.50, 92.85, and 44.73, respectively. In addition, FE-SEM confirmed that the previous samples consist of (spherical and cup), (tree leaves and cylindrical rods), (cylindrical rods and spherical), and (spherical and rods) shapes, respectively. Besides, characteristic vibrations of mordenite such as internal symmetric, external symmetric, internal asymmetric, external asymmetric, and bending were detected using FT-IR at 690-705, 780-795, 1025-1030, 1222-1235, and 447-464 cm(-1), respectively. The PEG-EG sample efficiently removed Pb(II) ions from aqueous media where 17.40 mg/g is the capacity value. Pore diffusion, intra-particle diffusion, pseudo-first-order, and liquid film diffusion kinetic models successfully described the removal of Pb(II) ions in the view of the kinetic study. In addition, Langmuir isotherm successfully described the removal of Pb(II) ions in the view of the equilibrium study. Moreover, the exothermic and chemisorption properties of the removal of Pb(II) ions were confirmed in the view of the thermodynamic study. The capacity of the PEG-EG sample or % removal of Pb(II) ions was not greatly affected after five desorption-adsorption cycles.