A new green synthesis of porous magnetite nanoparticles from waste ferrous sulfate by solid-phase reduction reaction

Porous magnetite nanoparticles have been successfully synthesized by a one-step reduction of waste ferrous sulfate with pyrite under nitrogen protection. In addition, the effect of calcination temperature, calcination time and the mass ratio of ferrous sulfate to pyrite on the particle size of porous magnetite nanoparticles were studied. The properties of magnetite nanoparticles synthesized were characterized via X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), superconducting quantum interference device magnetometer (SQUIDM) and Brunauer-Emmett-Teller (BET) method. The formation of magnetite nano particles with inverse spinel structure was verified by XRD, FFIR and XPS. TEM micrograph suggested that the cubic magnetite nanoparticles with particle size of 25-50 nm were obtained, the surface area and the pore volume of magnetite nanoparticles were estimated to be 10.6 m(2)/g and 0.059 cm(3)/g. Magnetization hysteresis curve exhibited the values of coercivity and remanence and saturation magnetization were found to be approximately 0.09 kOe, 7.9 emu-g(-1) and 77 emu-g(-1), respectively. (C) 2017 Elsevier B.V. All rights reserved.