Little Adjustments Significantly Simplify the Gram-Scale Synthesis of High-Quality Iron Oxide Nanocubes

Abstract

This work presents a facile one-step protocol for the gram-scale synthesis of iron oxide nanocubes with adjustable sizes ranging from 13 to 20 nm and with size distributions between 7 and 12%. As X-ray diffraction indicated the initial formation of the wustite phase, a formation mechanism of the nanocubes based on the wustite crystal structure is proposed. When exposed to ambient conditions, the nanoparticles rapidly oxidize to magnetite/maghemite with a remaining wustite core. The cubic morphology is attributed to the thermodynamic stability of the exposed {100} facets and the control over the growth rate via the use of a sodium oleate/oleic acid mixed ligand system. In contrast to previously reported procedures, the described synthetic approach does not require the initial preparation and isolation of iron oleate. Therefore, the amount of work and the consumption of hazardous solvents are significantly reduced. Thus, the method presented is much more efficient and environmentally more friendly while maintaining excellent control over the particles' shape, size, and size distribution.

Diversity of Iron Oxides: Mechanisms of Formation, Physical Properties and Applications

“…Based on the gathered information, it was possible to determine the most frequently obtained form of the structures containing FeO (Table 2). This form is FeO NPs produced for biomedical applications via various chemical or physical routes, but not naturally originated, since this iron oxide compound is metastable under normal conditions [42, [74][75][76][77][78][79][80].…”

Rectangular Cylinders Formed by Compositionally Bidisperse ABC Triblock Terpolymer Blends: A Self-Consistent Field Theory Study

“…Therefore, in materials such as nanowire arrays fabricated by the cylinder-forming BCPs, the cross-section of each single nanowire in the arrays is evidently circular. However, in recent years, large amounts of novel nanomaterials with nanostructure units having noncircular cross-sections are coming forth and showing a trend of rapid development. − Compared with nanostructure units that have circular cross-sections, nanostructure units with noncircular cross-sections, such as nanocube and rectangular nanobar (Figure b), have two unique features: (1) nanostructure units with noncircular cross-sections have shape anisotropies (e.g., square cross-section in Figure b), hence have different confined states of surface electrons and different surface plasmonic resonance features due to different curvatures on their surfaces; (2) nanostructure units with shape anisotropies can display various relative arrangements such as edge-to-edge, edge-to-corner, and corner-to-corner arrangements (Figure c), which apparently do not exist in nanostructure units with circular cross-sections. Both different confined states of the surface electrons and different relative arrangements endow materials possessing shape anisotropic nanostructure units with novel properties and functions.…”