Influence of Applied Voltage on Electrooxidation of Iron in the Cell Containing -cyclodextrine

Synthesis of functionalized iron oxide nanostructures has recently been attracting increased interest for many biomedical and biological applications [1]. It is a technological challenge tocontrol size, shape, stability, and dispersibility of nanoparticles [2-4]. Iron oxide nanoparticles possess high surface energies due to their large surface to volume ratio. Consequently, they tend to aggregate so as to minimize the surface energies. Also, they have high chemical activity.Therefore, providing proper surface coating and developing some effective protection strategies to keep the stability of magnetic iron oxide nanoparticles is very important. The present report focuses on the synthesis of functionalized magnetite nanoparticles with -cyclodextrinemolecules by applying different voltages. Here, magnetite nanoparticles were synthesized electrochemically using a chronoamperometric technique. Two purified iron plates of 1cm × 4cm and 1cm ×1cm were used as cathode and sacrificial anode, respectively. The electrodes werepolished mechanically by fine grain emery paper and then ultrasonically cleaned with ethanoland dried. The cleaned electrodes were mounted in an electrolytic bath containing 200 ml of 0.25 M Na2SO4 and -cyclodextrine as organic additive. In order to study the effect of applied voltageon structure and magnetic properties of the particles, a group of samples prepared by applying 5 V, 8 V, 11 V, and 14 V, keeping concentration and temperature at 0.03 M and 60°C. To understand the effect of -cyclodextrine on the properties of Fe3O4 nanoparticles, one referencesample was prepared in the electrolytic bath without any organic. The reaction time was chosenas 1800 s and electrolyte temperature was controlled using a thermostatic water bath. After applying appropriate potential difference the solution went through several color changes. After a few hundred of seconds the solution became black and the particles started to precipitate. The black precipitates washed several times with deionized water and then dried. X-ray diffraction, FT-IR spectroscopy, and electron microscopy were used to characterize the samples. X-raydiffraction patterns showed the formation of the spinel phase of Fe3O4. FT-IR spectra confirm the presence of organic molecules at the surface of particles. Electron microscope images showed the mean particle size is in the range 20-90 nm. The experimental parameters playsignificant role in determining the morphological and structural properties of the products. Based on these images we found that tuning the growth conditions has a strong effect on particle size and morphology. High resolution transmission electron microscope images showed the aggregation of very fine crystallite with different orientations. The results suggest that the particles have polycrystalline structures in nature.

Keywords:

Magnetite Nanoparticles , -cyclodextrine , Voltage , Electron Microscopy