Enhanced control of magnetite nanoparticle electrosynthesis through cyclic voltammetry

In this work, we report the electrosynthesis of magnetite (Fe₃O₄) nanoparticles using cyclic voltammetry with a carbon steel sacrificial anode in NaCl solutions. The study explored scan rates between 1 and 20 mV/s in NaCl concentrations of 0.01 M and 0.1 M. Comprehensive characterization using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) revealed that the slower scan rates and higher electrolyte concentrations promoted the formation of well-crystallized magnetite. At higher scan rates and lower NaCl concentrations, intermediate iron oxide phases such as goethite (α-FeOOH) and lepidocrocite (γ-FeOOH) were observed. The smallest crystallite size (18 nm) was obtained at 1 mV/s in 0.1 M NaCl, confirming that lower scan rates favor smaller and more uniform nanoparticles. This work highlights the influence of scan rate and electrolyte concentration on nanoparticle size, phase purity, and morphology, offering insights into controlling these parameters for optimized synthesis. The findings have significant implications for environmental applications such as water remediation and energy storage technologies.