Structural, Morphological, and Optical Properties of Single and Mixed Ni-Co Aluminates Nanoparticles

A series including single and mixed Ni-Co aluminates was obtained using the precursor method, with malic acid as a ligand. The malate precursors (polynuclear coordination compounds) were isolated and characterized by Fourier Transform Infrared (FTIR), Ultraviolet/Visible/Near Infrared (UV-Vis-NIR) spectroscopy, and thermal analysis. The UV-Vis-NIR spectra of the synthesized complex compounds highlighted the presence of Co2+ and Ni2+ in an octahedral environment. The thermal decomposition of these precursors led to Co1-xNixAl2O4 (x = 0, 0.1, 0.25, 0.5, 0.75, 0.9, and 1) spinels. The effect of Ni2+ substitution on the structure, morphology, and optical properties of the obtained oxides was studied with the help of different characterization tools. XRD, FTIR, and Raman spectra evidenced the formation of the spinel phase. The size of the crystallites and the agglomeration degree of the particles decrease when the nickel content increases. The band gap (BG) value is not significantly influenced by the Ni substitution. The fluorescence spectra recorded for all samples show a similar pattern, but different intensities of the emission bands.

Automated summary

In this study, a series of single and mixed Ni-Co aluminates were synthesized using the precursor method. The effects of nickel substitution on the structure, morphology, and optical properties of the obtained oxides were investigated. The results showed that the size of crystallites and the agglomeration degree of particles decreased with increasing nickel content, while the band gap value was not significantly affected by nickel substitution. The fluorescence spectra exhibited similar patterns but different intensities of emission bands for all samples.