Magnetite nanoparticles functionalized with polypyrrole by pulsed sono-electrocrystallization and their applications for water treatment

The influence of ultrasonic irradiation on structural and magnetic properties of functionalized magnetite/polypyrrole nanoparticles synthesized by the pulsed sono-electrocrystallization method was studied. X-ray diffraction patterns confirm that all samples have the inverse cubic spinel structure of magnetite. High-resolution transmission electron microscope images showed the formation of core/shell structure of iron oxide/polypyrrole nanoparticles. Electron microscope images demonstrate that an ultrasound wave produces significant changes in the particle size and morphology. Iron is almost all in the 55–100 nm particles of slightly nonstoichiometric Fe_3−δO₄, with 0.04 ≤ δ ≤ 0.14. The specific magnetization of the magnetite nanoparticles ranging from 45 to 75 Am² kg⁻¹ depends on the particle size, applied amplitude, and cycle of ultrasound waves. The application of magnetite/polypyrrole nanoparticles in removal of copper, nickel and cobalt from water was studied. The AAS results showed the magnetite nanoparticles functionalized by polypyrrole are particularly effective materials for copper, nickel and cobalt removal from water.