Novel Composites of Multifunctional NaP Zeolite/Graphene Oxide for Highly Efficient Removal of Fe(III) from Aqueous Solution

Composites of graphene oxide (GO, 1–5 wt%) loaded into the inter pores of the hollow NaP zeolite at 100 °C were successfully prepared via the zeolite synthesis method (ZSM). These NaP/GO composites were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy and N2 physisorption analysis. The structural properties of NaP/GO (1–3 wt%) indicated that GO moieties can be accommodated in the voids of the NaP zeolite without modifying its framework or structure. The FE-SEM image of NaP/GO (3 wt%) showed the tendency of GO to form significantly smaller individual particles of NaP zeolite than corresponding of NaP/GO (1 and 2 wt%). The FTIR band due to asymmetric stretching T–O lattice vibration (~ 1000 cm−1) was shifted towards higher frequencies with increasing content of GO (1–3 wt%), reflecting the involvement of GO adducts in the intracrystalline structure of NaP zeolite. The produced composites were used for the removal of Fe(III) ions from aqueous solution and such process took place via a surface uptake and intra-particle diffusion which operate simultaneously through the interaction between Fe(III) ions and NaP/GO (3 wt%). The dielectric constant (εr) values as a function of frequency were increased after adsorbing Fe(III) onto NaP/GO (3 wt%) which may be attributed to cations hopping diffusion along zeolite structure.