Capsule-like α-Fe2O3 nanoparticles: Synthesis, characterization, and growth mechanism

Uniform capsule-like a-Fe2O3 particles were synthesized via a simple hydrothermal method, employing FeCl3 and CH3COONa as the precursors and sodium dodecyl sulfate (SDS) as soft template. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy were used to characterize the structure of synthesized products. Some factors influencing the formation of capsule-like a-Fe2O3 particles were systematically investigated, including different kinds of surfactants, the concentration of SDS, and reaction times. The investigation on the evolution formation reveals that SDS was critical to control the morphology of final products, and a possible five-step growth mechanism was presented by tracking the structures of the products at different reaction stages.