Electrochemical synthesis of magnetic iron oxide nanoparticles with controlled size

Abstract

We present a novel and facile method enabling synthesis of iron oxide nanoparticles, which are composed mainly of maghemite according to X-ray diffraction (XRD) and Mössbauer spectroscopy studies. The proposed process is realized by anodic iron polarization in deaerated LiCl solutions containing both water and ethanol. Water seems to play an important role in the synthesis. Morphology of the product was studied by means of transmission electron microscopy and XRD. In the solution containing almost 100% of water a black suspension of round shaped maghemite nanoparticles of 20–40 nm size is obtained. Regulating water concentration allows to control nanoparticle size, which is reduced to 4–6 nm for 5% of water with a possibility to reach intermediate sizes. For 3% or lower water concentration nanoparticles are of a needle-like shape and form a reddish suspension. In this case phase determination is problematic due to a small particle size with the thickness of roughly 3 nm. However, XRD studies indicate the presence of ferrihydrite. Coercivities of the materials are similar to those reported for nanoparticle magnetite powders, whereas the saturation magnetization values are considerably smaller.

Alumina-based nanoparticles obtained by anodic dissolution of Al in electrolytes with alcohol solvents

“…Therefore, as specified in the precedent paragraph, higher potentials were chosen, which resulted in the highly efficient synthesis of nanoparticles. The addition of water to the solution influences the kinetics of anodic oxidation, similarly to other metals [17]. The influence of water concentration on the course of the anodic process is presented in Fig.…”

“…2. The presence of water in alcohol causes a passivation of aluminum surface in analogy to the cases of iron and other metals [17]. The increase of water content shifts desorption potentials to lower values and gives rise to the increase of current density in the dissolution range.…”

“…Electrochemical synthesis of various metal oxide nanoparticles has been proposed for different metals so far [15][16][17][18]. On the other hand, a production of nanoparticles based on aluminum anodic polarization is rather an unexplored subject.…”

Progress in the Preparation of Magnetite Nanoparticles through the Electrochemical Method

“…et al, 2002), (ii) hydrogen gas as a reducing agent of iron hydroxide (Franger S. et al, 2004;Manrique-Julio J. et al, 2016;Melnig V. and Ursu L., 2011), (iii) direct reaction between Fe 2+ and Fe 3+ (Karami H. and Chidar E., 2012;Ying T.Y. et al, 2002), and (iv) oxygen as oxidant agent and subsequent in-solution precipitation Gopi D. et al, 2016;Lozano I. et al, 2017;Pascal C. et al, 1999;Starowicz M. et al, 2011).…”

In situ One‐pot Electrochemical Synthesis of Aluminum Oxide/polyaniline Nanocomposite; Characterization and Its Adsorption Properties towards Some Heavy Metal Ions

“…Application of electrochemical method for generating metal oxide nanoparticles has been also reported. 23 Synthesis by electrochemical method can be performed by passing an electric current between two electrodes in an electrolyte, in which the anode can be oxidized to metal ion species in the electrolyte. The polyaniline family (PANI) is a group of conjugated conducting polymers which gain much interest because their unique conduction mechanism, bearing relatively high conductance, good stability in the presence of oxygen and water, and exhibiting chemical sensitivity.…”