Synthesis and Characterisation of Iron Oxide Nanoparticles with Tunable Sizes by Hydrothermal Method

TL;DR

This study explores how reaction time influences the size, shape, and crystallinity of iron oxide nanoparticles synthesized hydrothermally, revealing shape transitions and phase compositions.

Contribution

It provides a detailed analysis of how reaction time affects nanoparticle morphology, phase composition, and crystallinity in hydrothermal synthesis of iron oxide nanoparticles.

Findings

Reaction time alters nanoparticle shape from nanorods to distorted nanocubes.

Samples mainly contain Goethite and Hematite phases.

Crystallinity varies with synthesis duration.

Abstract

The present study investigates the effect of different reaction times on the crystallinity, surface morphology and size of iron oxide nanoparticles. In this synthetic system, aqueous iron (III) nitrate (Fe(NO$_3$)$_3\cdot9$H$_2$O) nonahydrate, provided the iron source and triethylamine was the precipitant and alkaline agent. The as-synthesised iron oxide nanoparticles were characterised by X-ray diffraction (XRD), Rietveld analysis, Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Prolonged reaction times indicated the change on nanoparticle shape from elongated nanorods to finally distorted nanocubes. Analysis on the crystallinity of the iron oxide nanoparticles suggest that the samples mainly consist of two phases, which are Goethite ($\alpha$-FeOOH) and Hematite $(\alpha$-Fe$_2$O$_3$), respectively.