Greener synthetic route for superparamagnetic and luminescent α-Fe2O3 nanoparticles in binary mixtures of ionic liquid and ethylene glycol

Abstract

α-Fe₂O₃ nanoparticles have been synthesized by a facile route employing inherently green binary mixtures of ionic liquid (IL), 1-ethyl-3-methyl imidazolium ethylsulphate, [C₂mim][C₂OSO₃] and ethylene glycol, EG. A room temperature grinding of Fe(NO)₃·9H₂O in the given binary mixture in the presence of NaOH led to the formation of amorphous particles, which on calcination, yielded α-Fe₂O₃ nanoparticles (NPs). The obtained NPs have been characterized by various state of the art techniques such as X-ray diffraction, Raman spectroscopy, UV-Vis and photoluminescence spectroscopy. The surface and morphological features of NPs have been investigated using scanning and transmission electron microscopy. The prepared NPs have shown weak ferromagnetic character with an essence of superparamagnetism as probed by vibrating sample magnetometry (VSM) and Mössbauer spectroscopy. The composition of the binary mixture of solvent has been found to affect the size, morphology and characteristic properties of the prepared α-Fe₂O₃ NPs.