Synthesis routes for multi-shape Fe3O4 nanoparticles through oxidation-precipitation of hematite and modified co-precipitation method without surfactant

Uniform fine particles of iron oxide were precipitated in different morphologies through forced hydrolysis and co-precipitation. The effect of reaction parameters on particle uniformity and morphology was studied, and SEM analysis explored that particle morphological features were strongly affected by the applied reaction conditions. Therefore, monodispersed particles of magnetite precursors with narrow size distribution were prepared under the extensively optimized experimental parameters. The growth mechanism of the precipitated solids was observed to be sensitive to the medium temperature and pH, as high temperature and pH resulted in large particles. In contrast, small particles were precipitated at low temperatures and pH. Magnetite nanoparticles were precipitated directly through co-precipitation under controlled reaction conditions and from the calcination of the as-synthesized hematite at high temperatures. Their SEM demonstrated that calcination at high temperatures affected the particle morphology to a greater extent along with the phase transformation. Similarly, XRD and FTIR analysis of the as-prepared magnetite particles from two routes confirmed the single-phase magnetite. The response of the as-prepared particle systems to the higher temperature and composition of the surface groups was analyzed by TG/DTA and FT-IR techniques.