2. Materials and methods
Manganese ferrite NPs were prepared in one step at room temperature following an electrochemical route, as shown in Fig. 1. The process involved the gradual release of Fe2 + and Fe3 + ions through the solution via application of a current density to the iron anode (8 cm2). A cylindrical counter-electrode of iron with an area of 120 cm2 was used as the cathode and placed around the anode. A current density of 50 mA/cm2 was applied and the purity of the Fe was 99.9% (Goodfellow). The Mn2 + ions were directly obtained using manganese chloride salt in solution (0.06 M of MnCl2·4H2O). A 0.04 M solution of R4NBr (R = Butyl) was employed as a surfactant, preventing agglomeration of nanoparticles during their synthesis. The solution was magnetically stirred throughout the electrosynthesis and a synthesis time of 1800s was employed. Subsequently, the nanoparticles obtained were magnetically separated from the solution, washed with distilled water and dried under vacuum at 60 °C for 24 h.