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 coprecipitation method and then calcinated at 600 o C 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 Co 2+ and Cr 3+ ions combined with Zr 4+ 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.

Controllable Cetrimide – Assisted Hydrothermal Synthesis of MoFe₂O₄ and Coupling with Al₂O₃ as an Effective Photocatalyst for Decolorization of Indigo Carmine Dye

“…After being altered under the same circumstances, the apparent rate constant for this photoreaction also increased. This cause is consistent with that which was mentioned in reference [43].…”

“…7, 8 and 9. that observed the band gap for MoFe 2 O 4 is direct [29] and equal to 2.78 eV (445.986 nm), while it is an indirect band gap for the α-Al This vital step to improve their optical properties when used as a photocatalyst because the spinel MoFe 2 O 4 has a small band gap that may be increased the recombination process but the coupling process will decline that via increase the charge separation and increase the hydroxyl radical life [42][43].…”

SDS-Assisted Hydrothermal Growth and Photocatalytic Activity of Like-Caviar MoFe₂O₄ Nanoparticle Decorated with Al₂O₃

“…Both the MoFe 2 O 4 and Al 2 O 3 solutions were dispersed for 2 h at 75 °C using ultrasonic waves at a frequency of 65 kHz. To accomplish the binding process between MoFe 2 O 4 and Al 2 O 3 , the MoFe 2 O 4 in the presence of SDS-surfactant solution was gradually added to the Al 2 O 3 solution over the course of 2 h at 75 °C; this procedure is similar and in agreement with the reported in the literature [26]. The light brown precipitate was filtered and washed with water and ethanol, then stored overnight in a desiccator.…”

“…Specifically for IC as an anion dye, a pH value of 5.3 was found. This demonstrates that although anion dyes have a pH value of < 7, which is acidic (+), any cation dyes have a pH value > 7, which is alkaline (−) [26].…”

“…That will improve the photocatalytic activity, though the charge carriers can migrate to MoFe 2 O 4 due to the higher VB potential of Al 2 O 3 . Moreover, this combined will elevate the acidity of the surface, which enhances the IC dye adsorption of the molecule over the catalyst surface and raises the generated hydroxyl radical, then direct attack of photogenerated holes [26,47].…”