Preparation and characterization of thiosemicarbazide functionalized graphene oxide as nanoadsorbent sheets for removal of lead cations

Abstract

A facial and novel method for removal of Pb +2 based on the appealing interaction between thiosemicarbazide modified graphene oxide nanosheets and Pb +2 are reported in this work. Textural and chemical characterization of graphite, graphene oxide, esterified graphene oxide and thiosemicarbazide modified graphene oxide nanosheets were investigated using thermogravimetric analysis (TGA), nitrogen adsorption at-196 o C, transmission electron microscopy (TEM), Xray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Adsorption of Pb +2 was confirmed by Langmuir model with maximum adsorption capacity of 192.7 mg/g for thiosemicarbazide modified graphene oxide nanosheets at 27 o C and initial pH value of 5.0. Kinetic studies showed that the adsorption of lead ions on the solid adsorbents follow pseudo-first order and Elovich kinetic models. Regeneration of graphene oxide, esterified graphene oxide and thiosemicarbazide modified graphene oxide nanosheets were studied using different eluents (H2O, 0.1 M HCl, 0.1 M EDTA) at different pH values. Both of disodium salt of ethylenediaminetetraacetic acid (EDTA) and HCl solutions (0.1M) are efficient eluents to desorb lead cations from the solid adsorbent surface. Desorption efficiency of HCl solution decrease with increasing its pH value.

Adsorption and Photo-Fenton Degradation of Methylene Blue Using Nanomagnetite/Potassium Carrageenan Bio-Composite Beads

“…The amount of MB desorbed into the desorption solution was calculated via a UV-Vis spectrophotometer. Desorption efficiency was calculated by the following equation [34].…”

Epoxy-Triazinetrione-Functionalized Magnetic Nanoparticles as an Efficient Magnetic Nanoadsorbent for the Removal of Malachite Green and Pb(II) from Aqueous Solutions

“…Hence, the removal of hazardous materials such as Pb­(II) and MG by a simple magnetic and recyclable adsorbent from water and wastewaters is very important from the economic point of view. − Among all adsorbents, surface-modified Fe 3 O 4 nanoparticles seem to be the best option for water and wastewater purification because of their easy separation and recycling from solution, availability, and relatively low price. The modification of magnetic nanomaterials with surface modifiers, especially OH- and NH-enriched components, has received much attention for the removal of organic and inorganic pollutants in recent years. − Triazine, a nitrogenized heterocyclic ring, has showed great potentials in the surface modification of nanomaterials to form efficient adsorbents for practical applications. Furthermore, the significant characteristic of triazinetrione-functionalized NPs is their potential to form host–guest complexes with pollutants in a broad pH range via electrostatic and Lewis acid–base interactions and surface complexation. − …”