Preparation of graphene oxide and nickel hexacyanoferrate composite for the effective removal of strontium ion from aqueous solution; characterization and application

Abstract

In the current work, the graphene oxide was synthesized through Hummer’s method and modified with nickel hexacyanoferrate nanoparticles. The product was characterized by a Scanning Electron Microscope (SEM) and Fourier Transform Infrared spectroscopy (FTIR). The characterization results confirm the successful synthesis of graphene oxide and the immobilization of nanoparticles on it. The obtained graphene oxide-nickel hexacyanoferrate (GO-NiHCF) was applied for the removal of Sr(II) from the aqueous media in the batch method. The influence of effective factors such as pH, time, and initial concentration of strontium on adsorption was studied. The pH study showed that Sr(II) uptake increases in the pH range of 1-7 and the uptake reduces slightly or remains constant at higher pH values. The adsorption capacity under optimum conditions was obtained at about 140 mg g-1 adsorbent. The kinetic data of Sr(II) sorption by GO-NiHCF were investigated by pseudo-first-order and pseudo-second-order models. The results showed that the kinetic data fitted well to the pseudo-second-order rate model. The equilibrium data suggest the data are relatively fitted well to the Langmuir adsorption isotherm. Therefore, it can be understood that adsorbents’ dispersion on graphene oxide sheets or interlayers is homogenous. The separation factor(RL) value extracted from the Langmuir curve was estimated as 0<RL<1, showing the sorption behavior is favorable.

Keywords

• adsorption
• graphene oxide
• nickel hexacyanoferrate
• strontium
• adsorbent
• wastewater