Functionalization and characterization of electrocrystallized iron oxide nanoparticles in the presence of β-cyclodextrin

• Published in: CrystEngComm 2016-01, Vol.18 (3), p.417-426
• Main Authors: Mosivand, Saba, Kazeminezhad, Iraj
• Format: Article
• Language: English
• Subjects: Crystal structure; Electron microscopy; Iron oxides; Magnetization; Nanoparticles; Spectra; Tuning
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/c5ce01789k

Electrocrystallized iron oxide nanoparticles were prepared by a chronoamperometric technique in the presence of β-cyclodextrin. The electrocrystallization process was performed with two iron electrodes in an electrolytic bath. The effect of β-cyclodextrin concentration, applied potential and bath temperature on the structural properties and magnetization of the nanoparticles was studied. FT-IR spectroscopy, X-ray diffraction, electron microscopy, magnetometry and Mössbauer spectroscopy were used to characterize the samples. XRD patterns confirmed the formation of the spinel Fe 3 O 4 crystal structure. FT-IR spectra confirmed the presence of organic molecules at the surface of the particles. Electron microscopy images showed that the mean particle size is in the range 20-80 nm. Based on these images, we found that tuning the growth conditions has a strong effect on the particle size and morphology. High-resolution transmission electron microscopy images showed the aggregation of very fine crystallites with different orientations. The lattice striations confirmed the well-crystallized nature of the nanoparticles. The ring-like electron diffraction patterns are attributed to diffraction from the crystal planes of iron oxide nanoparticles. Room-temperature magnetization loops showed that all samples are magnetically soft with very little hysteresis, but the specific magnetization ranging from 14-80 A m 2 kg −1 is highly dependent on the particle size and the experimental conditions. The room-temperature Mössbauer spectra are typical of non-stoichiometric Fe 3− δ O 4 , with a small excess of Fe 3+ (0.07 ≤ δ ≤ 0.18). Our results showed that it is possible to improve the crystal structure of the particles by tuning the growth parameters. Electrocrystallized iron oxide nanoparticles were prepared by a chronoamperometric technique in the presence of β-cyclodextrin.