LAUSR

Abstract Studies regarding the recovery of palladium ions from aqueous solutions through adsorption onto ionic liquid functionalized Zn-Al layered double hydroxides and the subsequent use of the exhausted adsorbent as photocatalysts in the degradation process of methylene blue are presented. For this purpose, three materials were synthesized: unmodified Zn3Al layered double hydroxide (LDH), a layered double hydroxide modified with methyl tri-alkyl ammonium chloride ionic liquid (IL) by ultrasonic impregnation and by co-synthesis. After sample characterization using XRD, FTIR, SEM and EDX techniques, the studied materials were employed as adsorbents in the Pd(II) ions recovery from aqueous solutions. It was proved that the presence of IL in the structure of the Zn3Al – LDH lead to an enhancing of the adsorption efficiency, especially when the co-synthesis method was used for the LDH functionalization. The resulted exhausted adsorbents were efficiently capitalized as photocatalysts in the degradation process of MB from aqueous solutions. The presence of ionic liquid in the structure of raw material Zn3Al and the presence of adsorbed Pd(II) ions onto the surface of the spent adsorbents, led to efficiencies of the photocatalytic methylene blue degradation above 90%.