Synthesis of novel α-Fe2O3 nanorods without surfactant and its electrochemical performance

Abstract

In the present work, a hydrothermal approach was employed for synthesis of α-Fe2O3 nanorods to improve electrochemical performance of hematite. The synthesis process was carried out using FeCl3.6H2O, as the metal salt, and KOH, as the precipitating agent. Presence of the chloride ion, pressure of the autoclave and presence of the surfactants are the three processing parameters, which have been investigated throughout this study. Ethylene glycol, oleic acid and CTAB were the three different surfactants implemented in this study. The cyclic-voltammetric test was applied in order to investigate the electrochemical performance of the as-prepared products. The results show that the morphology of α-Fe2O3 nanoparticles has been converted into nanorods by elimination of the chloride ions, thereby gaining a higher specific surface area by one-dimensional structure of nanorods and resulting in better electrochemical properties compared with the nanoparticles. The results clearly indicated that tuning pressure and presence of surfactant play key roles in obtaining various sizes of nanorods, regarding length and width. The diameter and length distribution diagram revealed that, at high pressure, diameters and lengths of the nanorods become smaller and longer, respectively. The results also demonstrated that applying ethylene glycol as a solvent and surfactant leads into the formation of smaller α-Fe2O3 nanorods, with regard to both length and diameter. Due to the high electrochemical properties and easily syntheses, α-Fe2O3 nanorods could be a promising candidate in electrochemical applications.