Facile Synthesis of Spinel CoCr2O4 and Its Nanocomposite with ZrO2: Employing in Photo‐catalytic Decolorization of Fe (II)(luminol-Tyrosine) Complex

Abstract

In this project, the deep green power from spinel cobalt chromite (CoCr2O4) nano-crystals carried out using the co-precipitation method and then calcinated at 600 oC for 4 hours. This produced nano-crystal (spinel CoCr2O4) fabricated using the ultrasonic technique to link it with zirconium dioxide (ZrO2) in ratios 1:2 and 1:3, respectively. The X-ray diffraction (XRD), scan electron microscopy (SEM), and energy-dispersive X-rays (EDX), as well as ultraviolet-visible spectrophotometry used to describe the characterizations of prepared materials. The XRD analysis demonstrated that the spinel CoCr2O4 synthesis and their composites were found to be nanoparticles. XRD spectra indicated that the spinel CoCr2O4 is successfully loaded on ZrO2, because, the 2θ of ZrO2 is shifted toward a high 2θ value after spinel CoCr2O4 loaded. This case is attituded to the tiny Co2+ and Cr3+ ions combined with Zr4+ in crystal lattice. The SEM images and EDX spectra of these obtained nanomaterials were found to be spherical agglomerations with an enhanced degree of surface roughness after surface fabrication. On the other side, the bandgap of spinel CoCr2O4 nanocrystals elevated from 3.2 to 4.8 eV with increasing the ZrO2 dose. Under UV-A light, the photocatalytic decolorization efficiency of Fe (II)-(luminol-Tyrosine) complex utilizing spinel CoCr2O4 nanocrystals was tested, and it increases from 17.57 % to 30.67% and 41.97% when its nanocomposite was used in 1:2 and 1:3 ratios, respectively. The elevated efficiency after modified the spinel CoCr2O4 surface with ZrO2 as nanocomposite, due to increasing the acidity of the spinel CoCr2O4 surface that enhances the adsorption of hydroxyl on its surface then generality of the hydroxyl radical, and reducing the recombination. The photoreaction using spinel CoCr2O4 nanocrystals, ZrO2, and their composites were followed pseudo-first-order kinetics depended on the complex concentration.