Photo-Chemical Synthesis of Iron Oxide Nanowires Induced by Pulsed Laser Ablation of Iron Powder in Liquid Media

Abstract

Iron oxide nanowires are synthesized by photochemical method through nanosecond pulsed laser ablation of iron powder in liquid media. The synthesis is tried using various wavelengths (248 and 532 nm) of pulsed laser at different liquids (water, ethanol, methanol, isopropanol and glycol). The solution of iron oxide nanowires is obtained only in methanol when the iron powder (size < 60 μm) is irradiated at 248 nm. Ablation with 532 nm in methanol resulted in solutions of iron oxide nanoparticles. It is very interesting to note that irradiating solutions of the nanoparticles, obtained via 532 nm ablation, with laser pulses at 248 nm laser gives rise to the solution of iron oxide nanowires again. It is to be recorded that only nanoparticles are obtained in water, ethanol, isopropanol and glycol when ablated with any of the said two lasers. Chemical and structural characterization suggest that the as-synthesized products are mainly amorphous goethite [FeO(OH)]. Annealing above 400°C, converts it into crystalline hematite (α-Fe2O3). The formation mechanism of the nanowires from extended 2D nanosheets is discussed.

Superparamagnetic amorphous iron oxide nanowires self-assembled into ordered layered structures

“…7 The research for the production of iron oxide nanowires has both theoretical and practical interest because these could be useful in a variety of elds, such as in medicine, 8 as biological and magnetic contrast, 9 as starting material for the preparation of photoconductors, 10 in biology, 11 in catalysis of carbon nanotube growth. 20 Unlike the routes used in the above mentioned studies, in this paper we present an efficient path for preparation of amorphous iron oxide nanowires by one-step method of thermal decomposition using m3-oxo trinuclear iron(III) acetate as precursor, dodecylamine, oleic acid and trichloroacetic acid in an appropriate ratio. The higher surface area induces a stronger magnetic eld perturbation over a larger volume more effectively for the outer sphere protons.…”

“…19 The photochemical method through nanosecond pulsed laser (248 nm) ablation of iron powder (size < 60 mm) in liquids (methanol) media leads also to iron oxide nanowires. 20 Unlike the routes used in the above mentioned studies, in this paper we present an efficient path for preparation of amorphous iron oxide nanowires by one-step method of thermal decomposition using m3-oxo trinuclear iron(III) acetate as precursor, dodecylamine, oleic acid and trichloroacetic acid in an appropriate ratio. The composition, properties and behaviour of the nanowires were determined by spectral method (FTIR, SAXS, XRD, and Mössbauer), microscopy (TEM), thermal methods (TGA, DSC), POM and SQUID magnetometry in order to have a clear image of this material's properties for future possible uses.…”

Synthesis and Characterization of Iron Oxyhydroxide Nanowires

“…Several studies concerning beta and gamma phase oxyhydroxide nanowires ( FeOOH and FeOOH) have been done [12]. Amorphous and crystalline (orthorhombic phase) goethite FeOOH nanowires, with diameters between 10 and 80 nm, and 0.6 to 1.2 m of length, have been obtained by laser ablation and hydrothermal techniques [13]- [15]. However, some parameters, like periodic arrays of nanowires, cannot be controlled and the possible techniques to order them require several steps.…”

“…However, some parameters, like periodic arrays of nanowires, cannot be controlled and the possible techniques to order them require several steps. Synthesis methods of goethite nanowires have received much interest as an intermediary for obtaining hematite nanowires, however, growing procedures are often complicated and/or expensive [13], [16], [17]. A simple method for obtaining nanowires right from synthesis process is lacking.…”