Facile Organometallic Synthesis of Fe-Based Nanomaterials by Hot Injection Reaction.

Georgia Basina,George Hadjipanayis,Vasileios Tzitzios,Nikolaos Tzitzios,Hafsa Khurshid

doi:10.3390/nano11051141

Abstract

Fe-based colloids with a core/shell structure consisting of metallic iron and iron oxide were synthesized by a facile hot injection reaction of iron pentacarbonyl in a multi-surfactant mixture. The size of the colloidal particles was affected by the reaction temperature and the results demonstrated that their stability against complete oxidation related to their size. The crystal structure and the morphology were identified by powder X-ray diffraction and transmission electron microscopy, while the magnetic properties were studied at room temperature with a vibrating sample magnetometer. The injection temperature plays a very crucial role and higher temperatures enhance the stability and the resistance against oxidation. For the case of injection at 315 °C, the nanoparticles had around a 10 nm mean diameter and revealed 132 emu/g. Remarkably, a stable dispersion was created due to the colloids’ surface functionalization in a nonpolar solvent.

Highlights

A plethora of methodologies have been developed for their synthesis in both aqueous and non-aqueous media including co-precipitation [12,39], the polyol reaction [40,41,42], and thermolytic reactions at high temperature in an organic environment [43,44], which lead to the formation of monodispersed nanoparticles with controllable size, shape, and morphology [44,45,46,47]
A common synthesis process of metallic Fe particles is the thermal decomposition of Fe(CO)5 in many different organic solvents such as octadecene [48,49] with a saturation magnetization up to 102 emu/g, octyl ether [33], and kerosene [50,51], showing 150 emu/g, while the reaction was taking place, after purification of the reactants, at room temperature in an oxygen free environment inside a glovebox
We report on a facile organometallic approach based on the instantaneous thermal decomposition of Fe carbonyls in a multi-surfactant-based media, which leads to the synthesis of Fe-based nanomaterials from the Fe/Fe-oxide core/shell to hollow Fe-oxides

Summary

Introduction

Nanomaterials 2021, 11, 1141. https://Colloidal magnetic nanoparticles, with well-defined morphology and dimensionality, are of primary importance for both fundamental studies and prospective applications in many technological areas including magnetic storage devices [1,2], ferrofluids [3,4,5], magnetic resonance imaging [6,7,8,9,10], drug delivery [11,12,13,14], bio-separation [15,16,17], hyperthermia [18,19,20,21,22], sensing [23,24,25], and catalysis [26,27,28,29]. Amongst them iron-based magnetic materials including iron oxides [30,31,32], metallic iron [33,34,35], and iron alloys [36,37,38]. Taking into consideration the synthesis of metallic iron nanoparticles and iron nanoalloys, well-defined morphologies in low dimension regimes and their stabilization against oxidation are challenges still to be overcome. A common synthesis process of metallic Fe particles is the thermal decomposition of Fe(CO) in many different organic solvents such as octadecene [48,49] with a saturation magnetization up to 102 emu/g, octyl ether [33], and kerosene [50,51], showing 150 emu/g, while the reaction was taking place, after purification of the reactants, at room temperature in an oxygen free environment inside a glovebox. A frequent synthesis method is the decomposition of iron(II) bis(trimethylsilyl)amide (Fe[NSi(CH3 )2 ]2 ) [52] and the reduction of iron(III) acetylacetonate [53,54]

Methods

Results

Conclusion