Stability of ZnO and Curcumin Decorated Graphene Oxide Nanocomposite in Acidic and Alkaline pH for Efficient Removal of Toxic Cd (II) Ions From Water

A nanocomposite of graphene oxide, zinc oxide, and curcumin (GO-ZnO-cur) was synthesized for the adsorption of toxic Cd (II) ions from water. The nanocomposites with different concentrations were characterized by FESEM, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and contact angle measurement. GO-ZnO-cur nanocomposites had a specific surface area of 18 m
²
/gm and were rich in hydroxyl and carboxyl groups. The hydrophilicity and stability over a range of pH of the composite were enhanced by optimization of curcumin concentration. The contact angle of the nanocomposite was 27.06° as compared to 37.13° for graphene oxide. Adsorption studies showed that GO-ZnO-cur nanocomposite could eliminate 90% of Cd (II) from water and had an adsorption capacity of 1568 ±10 mg/gm at neutral pH and room temperature.