aqueous synthesis of sub-11 nm fe-cu oxides and alloy nanostructures: structural and morphological studies

Fe and cu oxides and fe-cu alloy nanostructures (fecuns) were obtained using a facile chemical reduction of different mass ratios of fecl2∙4h2o and cucl2∙2h2o with nabh4 in an aqueous solution, under nitrogen atmosphere. fecuns were prepared in three different fe:cu ratios: 75:25, 50:50, and 25:75 wt. %, by an aqueous reduction. fecuns were characterized by scanning electron microscopy (sem), x-ray photoelectron spectroscopy (xps), x-ray diffraction (xrd), transmission electron microscopy (tem), and high-resolution tem (hrtem), and their textural properties were determined using nitrogen physisorption. synthesized fecuns sizes ranged from 2.2 to 11 nm, having an irregular quasi-spherical morphology. the main phases in these nanostructures, as determined by xrd, are fe2o3, fe3o4 and cufe2o4; the main peak obtained at 2θ = 43.33° confirmed the formation of the nanoalloy fe-cu, as fecu4 (jcpds no.065-7002) in the 50:50 and 25:75 wt.% fecuns samples, which can be indexed as a face-centered cubic structure (fcc). an xps study performed on these nanostructures allowed for confirming the formation of the fecu4 alloy, alongside other metallic oxide main phases.