Citrate Assisted Synthesis of co-Doped ZnAl2O4 with La3+ and Pb2+ Ions and Applications; Adsorption-Photocatalysis

H. Filalia, N. Boukheita, R. Bouhroumb, W. Chekiroua, A. Karaalia aLaboratoire de Thermodynamique et Traitements de Surface des Matériaux, Université Frères Mentouri, Constantine 1, Route de Ain El-Bey, 25000, Constantine, Algeria bLaboratoire des Techniques Innovantes et Préservation de l'Environnement, Université Frères Mentouri Constantine 1, Route de Ain El-Bey, 25000, Constantine, Algeria

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Samples of pure zinc aluminate (ZnAl2O4) and doped ZnAl2O4 with both lead (Pb2+) at different ratios (0, 0.5, 1, 1.5, 2, 2.5 mol%) and a constant amount of lanthanum (La3+: 1 mol%), were prepared by the citrate sol-gel technique, and then annealed at 900° for 2 h. To study the structural, optical, and thermal properties, different characterization methods were used such as powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, the Fourier transform infrared spectroscopy and the Raman spectroscopy. Analysis by X-ray diffraction revealed the presence, in all samples, of the cubic, single-phase ZnAl2O4 without any impurity phases, with a crystallite size between 19 and 25 nm. These results were confirmed using the Fourier transform infrared and the Raman spectroscopy. Also ultraviolet spectra indicated that the bandgap of the doped samples decreases and exhibits a redshift with increasing concentration of Pb2+ ion. In addition, the photocatalytic study for different samples of ZnAl2O4 showed that they could be used as photocatalysts and good adsorbents for the degradation of a hexamethyl crystallized violet dye in an aqueous solution.

DOI:10.12693/APhysPolA.140.379 topics: nanoparticles, sol-gel, photocatalysis, adsorption