Synthesis and characterization of nickel aluminate nanoparticles

In the work, a simple synthesis route for obtaining NiAl2O4 nanoparticles was developed. The synthesis route used commercial aluminium foil (Al-0) reacting with a solution of nickel (II) chloride (NiCl2) dissolved in a 25:75 Toluene/THF mixture in a controlled helium atmosphere. The reduction synthesis was carried out at 60 degrees C for 72 h. The phase transformation temperatures of the powder were determined through differential scanning calorimetry and thermal gravimetric analysis (DSC/TGA). The resulting mixture was dried at 80 degrees C, followed by sintering heat treatments at 500 degrees C, 700 degrees C, and 1100 degrees C, respectively. The powder samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-vis), attenuated total reflectance (ATR), x-ray photoelectron spectroscopy (XPS) and highresolution transmission electron microscopy (HR-TEM) analysis. The results showed the formation of a single NiO phase when sintered at 500 degrees C and a nickel aluminate (NiAl2O4)-nickel monoxide (NiO) biphasic mixture after 700 degrees C and 1100 degrees C calcinations. The NiAl(2)O(4 )nanoparticles displayed an average crystallite size of 13 to 19 nm while the NiO particles are at micrometric size due to the elevation of the sintering temperature.