Green Synthesis of Nano Zinc Oxide/Nanohydroxyapatite Composites Using Date Palm Pits Extract and Eggshells: Adsorption and Photocatalytic Degradation of Methylene Blue
Abstract: In this study, zinc oxide nanoparticles (ZnO) and nanohydroxyapatite (NHAP) were
prepared in the presence of date palm pits extract (DPPE) and eggshells, respectively. Another four
nanocomposites were prepared from ZnO and NHAP in different ratios (ZP13, ZP14, ZP15, and
ZP16). DPPE and all nanomaterials were characterized using GC-MS, zeta potentials, particle size
distributions, XRD, TEM, EDX, FTIR, and pHPZC. The characterization techniques confirmed the
good distribution of ZnO nanoparticles on the surface of NHAP in the prepared composites. Particles
were found to be in the size range of 42.3–66.1 nm. The DPPE analysis confirmed the presence of
various natural chemical compounds which act as capping agents for nanoparticles. All the prepared
samples were applied in the adsorption and photocatalytic degradation of methylene blue under
different conditions. ZP14 exhibited the maximum adsorption capacity (596.1 mg/g) at pH 8, with
1.8 g/L as the adsorbent dosage, after 24 h of shaking time, and the static adsorption kinetic process
followed a PSO kinetic model. The photocatalytic activity of ZP14 reached 91% after 100 min of
illumination at a lower MB concentration (20 mg/L), at pH 8, using 1.5 g/L as the photocatalyst
dosage, at 25 C. The photocatalytic degradation of MB obeyed the Langmuir–Hinshelwood firstorder
kinetic model, and the photocatalyst reusability exhibited a slight loss in activity (~4%) after
five cycles of application.
Publication year 2022
Organization Name
Author(s) from ARC
Publication Type Journal
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