Synthesis of Magnetite Nanoparticles Using The Reverse Co-precipitation Method With NH4OH as Precipitating Agent and Its Stability Test at Various pH

In this study, the synthesis of magnetite was carried out through the reversed coprecipitation method with ammonium hydroxide (NH4OH) as precipitating agent. The aim of the study was to obtain the most appropriate moles ratio of Fe(III) and Fe(II) in obtaining the best characteristics of magnetite, considering that Fe (II) was easily oxidized to Fe (III). Characterization of synthesized magnetite was performed using a Fourier Transform Infrared (FTIR) spectrophotometer and X-Ray Diffraction (XRD). The results showed that the moles ratio of Fe (III) and Fe (II) that produced magnetite with high yield, FTIR spectra absorption and diffractogram peaks with high intensity was magnetite synthesized using a ratio of Fe (III) and Fe (II) = 1.5: 1. Yield of magnetite synthesized in this condition was 81%. Based on the stability test, magnetite was stable at pH 2-10.