From iron coordination compounds to metal oxide nanoparticles

Abstract

Various types, shapes and sizes of iron oxide nanoparticles were obtained depending on the nature of the precursor, preparation method and reaction conditions. The mixed valence trinuclear iron acetate, [Fe2 IIIFeIIO(CH3COO)6(H2O)3]·2H2O (FeAc1), μ3-oxo trinuclear iron(III) acetate, [Fe3O(CH3COO)6(H2O)3]NO3∙4H2O (FeAc2), iron furoate, [Fe3O(C4H3OCOO)6(CH3OH)3]NO3∙2CH3OH (FeF), iron chromium furoate, FeCr2O(C4H3OCOO)6(CH3OH)3]NO3∙2CH3OH (FeCrF), and an iron complex with an original macromolecular ligand (FePAZ) were used as precursors for the corresponding oxide nanoparticles. Five series of nanoparticle samples were prepared employing either a classical thermal pathway (i.e., thermal decomposition in solution, solvothermal method, dry thermal decomposition/calcination) or using a nonconventional energy source (i.e., microwave or ultrasonic treatment) to convert precursors into iron oxides. The resulting materials were structurally characterized by wide-angle X-ray diffraction and Fourier transform infrared, Raman, energy-dispersive X-ray, and X-ray fluorescence spectroscopies, as well as thermogravimetric analysis. The morphology was characterized by transmission electron microscopy, atomic force microscopy and dynamic light scattering. The parameters were varied within each route to fine tune the size and shape of the formed nanoparticles.

One-pot combustion synthesis of nickel oxide and hematite: From simple coordination compounds to high purity metal oxide nanoparticles

“…Although many synthetic approaches were developed [31][32][33][34][35][36][37][38][39], emphasis should be pointed out to thermal decomposition of suitable precursors for the preparation of functional oxide nanomaterials with tailored properties at mass scale [40]. Coordination compounds, such as metal carbonyls, metal acetylacetonates, and metal carboxylates, have been profoundly investigated as precursors to fabricate nanostructured metal oxides with desired morphology by thermal decomposition [40][41][42][43][44][45][46][47]. Organic solvents are widely used in thermal decomposition methods, to lower reaction temperatures and provide uniform and narrow size distribution of nanoparticles [40,48].…”

Nanomaterials Developed by Processing Iron Coordination Compounds for Biomedical Application

“…In addition, transmission electron microscopy (TEM) images of nanowires heated in nitrogen atmosphere at 700°C show formation of nanoparticles with various sizes including nanotubes. This approach was also applied for preparing iron oxide with various shapes: cubic, spherical, and hair-like structures, protruding from the surface at various angles, but generally in a radial direction from the sphere center [87]. Iron-chromium oxide nanoparticles of 11 nm were obtained using μ 3 -oxo heterotrinuclear (FeCr 2 O) acetate as metals precursor, oleic acid and dodecylamine as surfactants, and trichloroacetic acid as solvent heated at 320°C for 1 h. The molar ratio of iron and chromium in the obtained nanoparticles was similar to the precursor.…”

“…Amorphous iron-chromium oxide nanoparticles of 3.5 nm were prepared by the thermal decomposition of μ 3 -oxo heterotrinuclear (FeCr 2 O) acetate in the presence of dodecylamine, sunflower oil, and trichloroacetic acid at 320°C for 1 h. According to XRD results, the formed nanoparticles remained amorphous even after 2 years. Solvothermal method was used to study the influence of surfactant concentration (dodecylamine and sodium oleate) and the type of solvent on decomposition at 200-250°C of μ 3 -oxo trinuclear iron acetate ([Fe 3 O(CH 3 COO) 6 (H 2 O) 3 ] NO 3 •4H 2 O) into IONPs [87]. It was found that both dodecylamine and sodium oleate concentrations influence the size and the shape of the resulted nanoparticles, while the chosen solvent did not greatly affect their morphology.…”

“…Ultrasonication of μ 3 -oxo trinuclear iron acetate in a strong alkaline medium for 5 and 30 min resulted in amorphous iron oxide. By thermal treatment of the as-prepared amorphous oxidic material at 400°C, 20 nm spheroidal hematite nanoparticles can be easily obtained [87]. It was shown that microwave irradiation of μ 3 -oxo trinuclear iron acetate in an alkaline medium leads to the formation of amorphous irregularly shaped IONPs when the pH of the reaction mixture was adjusted to 11, while at pH 12 agglomerates of hematite nanorods of approximately 15 nm in width and 10 nm irregularly shaped nanoparticles were obtained [87].…”

“…A poly(siloxane-azomethine) iron(III) coordination compound can be prepared following the procedure described in reference [95]. Calcination at 600°C for 5 h in air of this iron complex based on a siloxane containing macromolecular ligand results in 29 nm core-shell nanoparticles, where the core consists of hematite and the shell of silica [87]. Nanoparticles with completely different morphology were prepared by calcination in the same condition of μ 3 -oxo trinuclear iron acetate and μ 3 -oxo trinuclear iron furoate, when polydisperse (50-350 nm) hematite and iron chromium oxide nanoparticles resulted.…”