Structure control synthesis of iron oxide polymorph nanoparticles through an epoxide precipitation route

Abstract

Iron oxide polymorph nanoparticles (magnetite, goethite and lepidocrocite) were synthesised through a novel epoxide precipitation route. Epoxide, as a precipitating agent, induced the precipitation of iron(II) ions in the form of hydroxide through its reaction with aquocomplexes of Fe 2þ ions. The organic intermediate, which was produced from the ring-opening reaction of epoxide, functionalised the surface of the formed precipitate in situ, resulting in the minimisation of the nanoparticles' aggregation. Another advantage of this route is its simple procedure for the preparation of iron oxide nanoparticles with different structures and their well-defined morphology. Magnetite, goethite and lepidocrocite nanoparticles were obtained just by the pH regulation and air oxidation at room temperature.

Progress toward Room-Temperature Synthesis and Functionalization of Iron-Oxide Nanoparticles

“…Fe-O stretching vibrations correlated with nano γ-Fe 2 O 3 are located at 630, 567, and 437 cm −1 [ 25 , 26 ]. The peaks at 890 and 795 cm −1 correspond to the Fe-O-H bending vibration bands, a characteristic of the α-FeOOH phase [ 27 , 28 , 29 ]. Additionally, in accordance with the DRX and Raman results, the M4 sample does not present the α-FeOOH phase.…”

Colloidal Synthesis of an Exotic Phase of Silicon: The BC8 Structure

“…New polymorphs of various phases have been discovered as nanomaterials via colloidal routes. − It has been recognized that both energetics and mechanism of formation are important for accessing the metastable phases via colloidal chemistry . For example, iron oxide polymorphs were synthesized via epoxide precipitation approach, and by changing the pH of the solution different polymorphs (magnetite, goethite, and lepidocrocite NPs) were formed . In another example, Pan et al have shown that Cu–In–S ternary phases could be synthesized in either the zincblende or wurtzite structures by changing the capping agent.…”

The Effect of High Selenite and Selenate Concentrations on Ferric Oxyhydroxides Transformation under Alkaline Conditions

“…Negligible structural changes and rearrangements of iron during maturation of ferric precipitates are also illustrated by ATR-FTIR spectra in Figure 3a. There are two strong absorbance bands at 885 and 796 cm −1 in the hydroxyl deformation region, labelled as δ(OH) and γ(OH), respectively, that can be assigned to goethite's characteristic vibrations [45,46], and provide some information on its crystallinity and substitution in mineral structures [45]. δ(OH) and γ(OH), respectively, that can be assigned to goethite's characteristic vibrations [45,46], and provide some information on its crystallinity and substitution in mineral structures [45].…”

“…There are two strong absorbance bands at 885 and 796 cm −1 in the hydroxyl deformation region, labelled as δ(OH) and γ(OH), respectively, that can be assigned to goethite's characteristic vibrations [45,46], and provide some information on its crystallinity and substitution in mineral structures [45]. δ(OH) and γ(OH), respectively, that can be assigned to goethite's characteristic vibrations [45,46], and provide some information on its crystallinity and substitution in mineral structures [45]. Since the vibrational bands between 1800 and 1000 cm −1 generally belong to water bending modes, the bands observed at ~1650 cm −1 can be assigned to the bending vibration of weakly adsorbed molecular water [47].…”