Precursor dissolution temperature as a size-controller in Fe3O4 submicrospheres syntheses and their effect in the catalytic degradation of Rhodamine B

Abstract

Iron oxides submicrospheres have been synthesized by a solvothermal method. The particle sizes decrease from 700 to 100 nm as a function of dissolution temperature of iron salt precursors, when keeping the reaction temperature in the autoclave constant. The submicrosphere particles are formed by aggregation of smaller nanoparticles, nanograins. The Fe₃O₄ submicrospheres show high saturation magnetization (M_s) and low hysteresis (low remnant magnetization, M_r and coercivity, H_c), showing superparamagnetic behavior. The size tailoring of the iron oxide particles allowed their application as catalysts on the photo-Fenton reaction of Rhodamine B degradation, in which smaller particles showed high catalytic activity and the degradation efficiency showed strong dependence on the nanograin size.