Copper aluminate spinel by soft chemical routes

Copper aluminate spinel (CuAl2O4) was obtained by two different chemical routes: the precursor method and the solution combustion method involving glycine-nitrates. The polynuclear complex compounds: (NH4)2[CuAl2(C4O6H4)3(OH)4]·2H2O (I), (NH4)[CuAl2(C6O7H11)3(OH)6]·2H2O (II) and [CuAl2(NH2CH2COOH)4.5]·(NO3)8·4H2O (III) were characterized by elemental chemical analysis, infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-vis) and thermal analysis. The final oxide powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), IR, Raman spectroscopy (RS), UV-vis and photoluminescence (PL) spectroscopy. X-ray diffraction patterns indicated the formation of the cubic phase CuAl2O4 with good crystallinity. The crystallite size ranged from 18.70 to 19.50 nm. Electron microscopy revealed the morphology corresponding to the complete crystallization into CuAl2O4. The band gap values ranged between 1.97 and 2.03 eV. The photocatalytic degradation of methyl orange (MO) was investigated using copper aluminate as catalyst.