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Introduction: Layered double hydroxides (LDHs) are widely studied anionite clays consisting of positively‐charged hydroxide nanosheets which is described by the general formula: [M(II)1−xM(III)x(OH)2][An−·mH2O], where M(II) and M(III) are the divalent (e.g., Mg2+, Zn2+, Ca2+, Co2+, Ni2+, etc.) and trivalent (e.g., Al3+, Fe3+, Cr3+, etc.) metal ions, An− and H2O is the interlamellar anion (e.g., Cl¯, Br¯, NO3¯, CO32¯, SO42¯, SeO42¯) for charge‐neutralization and hydrated state, respectively. They have been widely used in different industry sectors, in materials science and research. Polymer/LDH nanocomposites have gained significant attention in recent years. Carbon‐based nanomaterials, like fullerene, carbon nanotubes (CNT), graphene and graphene oxide have attracted significant attention. Fullerene molecules (C60, C70) are used as reinforcing material for polymers to improve their mechanical, thermal, optical, energy storage and charge transport properties. Objectives: C60‐doped ZnAl‐layered double hydroxide/polyvinyl alcohol nanocomposites were successfully synthesized and their photocatalytic activity for photodegradation of methylene blue (MB) synthetic dye was quantitatively analyzed by ultraviolet (UV) spectroscopy. The effect of C60 on the optical, structural, morphological properties, and photocatalytic activity of LDHs was investigated, and the impact of C60/LDH mass ratio and aging time on the properties was also studied. Methods: Fullerene‐doped ZnAl‐LDH/PVA nanocomposites were synthesized via urea hydrolysis and coprecipitation‐coformation method. First, 10 wt% PVA/water solution (40 mL) is added into the mixed solution containing 0.015 mol of Zn(NO3)2·6H2O and 0.005 mol of Al2(SO4)3·9H2O and titrated by 2 M of NaOH and 1 M of NaHCO3 mixed base solution to adjust pH 9. The obtained white slurry was shaken very hard and aged for 1 year. The obtained samples were marked by the mass percentage of C60 as 1% C60@LDH/PVA, 10% C60@LDH/PVA, 20% C60@LDH/PVA, and 60% C60@LDH/PVA. Results and Discussion: The basal spacing of C60‐doped ZnAl‐LDH was estimated to be 9.217 Å which is wide enough from the general LDH (~7.0 Å). The crystallite size of nanoparticles is 9.217 nm and ~6 nm by Scherrer's equation and Williamson–Hall method from the XRD data, respectively. Rice‐shaped 2D morphology was formed with 100 nm–2 μm width and 500 nm–10 μm in length by SEM. The maximal photodegradation efficiency was found with 20% of C60 doping (PD% = 96.98) after 360 min, where the sorption efficiency with this compound is very high (R% = 85.55). Conclusions: In the presented work, the effect of C60 on the optical, structural, morphological properties, and photocatalytic activity of LDHs was investigated, and the impact of C60/LDH mass ratio and aging time on the properties was also studied. For the identification of the photocatalytic activity of obtained C60/LDH nanocomposites, MB was used as a model pollutant and the efficiency of the Zn/Al LDH nanocomposite, with various quantities of fullerene, is also evaluated. [ABSTRACT FROM AUTHOR]

In this study one-pot synthesis of zinc-aluminum mixed oxide/polyvinyl alcohol (ZnAl mixed oxide/PVA) nanocomposite and its adsorption behavior for efficient removal of lead (II) ions from aqueous solution were investigated. The synthesized nanocomposite was characterized by X-ray diffraction (XDR), Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and Ultraviolet-visible spectroscopes (UV-Vis) to study structural, optical properties, morphology and elemental composition. Two characteristic reflections of ZnO and Zn6Al2O9 phases were shown by the XRD pattern of the nanocomposite. Due to PVA strongly caped the particles, the subsequent growth of the nanoparticle was prevented and estimated as 10.5 and 7.8 nm for ZnO and Zn6Al2O9 crystallites, respectively. The concentration of Pb(II) in a solution was investigated by Inductively coupled plasma - optical emission spectrometry (ICP-OES). The optimum pH for the uptake of Pb(II) on ZnAl mixed oxide/PVA was 5.0. The removal efficiency of Pb(II) reached up to ∼97% after 180 min when 0.03 g ZnAl mixed oxide/PVA was added in 10 mL Pb(II) solutions which the concentration was 331.4 mg/L (10-3 M) at the condition of neutral pH and 298 K. Pseudo-second-order kinetic model and Freundlich isotherm were found to be the most suitable models to define the adsorption mechanism in this process. Thermodynamic parameters like ΔH°, ΔS°, ΔG° and Ea of the adsorption of Pb(II) ions onto ZnAl mixed oxide/PVA are estimated -72.98, −0.222, −6.737 and 25.956 kJ/mol at the condition of neutral pH and 298 K. After 9 cycles the % removal of Pb(II) ions reduced to 63.177%. [ABSTRACT FROM AUTHOR]