Nanostructured copper aluminate spinels: Synthesis, structural, optical, magnetic, and catalytic properties

Copper aluminate nanostructured materials were synthesized by a microwave combustion method (MWCM) using the plant extract (aloe vera) as a fuel without using any other template or surfactant. For comparison, it was also prepared by using the conventional combustion method (CCM). The as-synthesized copper aluminate was characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, nitrogen adsorption/desorption isotherms, and vibrating sample magnetometer (VSM). The results indicated that the copper aluminate nanomaterials obtained by MWCM shows good crystallinity with the uniform size distribution than the ones prepared by CCM. The XRD and FT-IR results confirmed the crystal structure of copper aluminate. The formation of copper aluminate nano- and microstructures were confirmed by HR-SEM. The optical absorption and photoluminescence emissions were determined by DRS and PL spectra, respectively. The effect of the catalyst and the oxidant on the catalytic oxidation of benzyl alcohol was also investigated.