A Novel Method for the Removal of Uranium by Using Carboxyl Functionalized Graphene Oxide

Abstract

Graphene oxide (GO) and functionalized carboxylic graphene oxide (COOH-GO) were successfully synthesized by modified Hummer’s technique. The prepared GO and COOH-GO was characterized successfully by UV-Visible Spectroscopy, Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction, Raman spectroscopy, Scanning electron microscopy (SEM)& Zeta potential. The removal of U(VI) heavy metal comparative study was done by using Graphite, GO & COOH-GO and the removal were confirmed by using LED fluorimeter. The effect of pH of medium, contact time, adsorbent dose, initial concentration of U(VI) were examined for the removal of U(VI). The extent of U(VI) removal has been found to be in the order of COOH-GO >GO> graphite. The U(VI) removal maximum efficiency was observed ~96% observed at pH 4.5. The higher removal efficiency is attributed to the higher negative surface charge of COOH-GO (zeta potential:-39.9 mV) in comparison to zeta potential of GO (-28.9 mV) &graphite (-21.6 mV).

Synthesis of carboxylic graphene oxide‐carboxymethyl chitosan composite and its applications toward the remediation of U6+, Pb2+, Cr6+, and Cd2+ ions from aqueous solutions

“…The COOH‐GO materials have exfoliated structures, whereas the surfaces of composite materials are found to be more porous than COOH‐GO, which makes them more suitable to be used as an adsorbent. [ 21,30,34 ]…”

“…In strongly acidic solutions (pH < 4.0), more protons are available to protonate amine groups, and the predominant species is UO 2 2+ , due to electrostatic repulsion, fewer binding sites are available for U 6+ ions, leading to a low removal percentage at low pH. [ 21,30 ] The COOH‐GO‐CMC shows maximum uranium removal of 96.4% at pH 5 due to the presence of free amine sites and U 6+ ions. [ 37 ] The surface charge of the composite is reversed at pH > 5.…”

“…The COOH‐GO was prepared and discussed in our published research work. [ 30 ] In the current research work, COOH‐GO‐CMC was synthesized from COOH‐GO and CMC. Firstly, 2 g of COOH‐GO were ultrasonically processed for 60 min in 500 ml of millipore water to develop a sponge‐like material of COOH‐GO.…”

“…The HTMIs percentage (%) removals were calculated by using Equation (1), and the maximum adsorption capacity (Q) was calculated by using Equation (2) in mg g −1. [ 21,30 ] where C i , C e , V, and m represent the initial concentration (mg L −1 ) of HTMIs prior to removal, the final concentration (mg L −1 ) of HTMIs after removal, the volume (mL) of aqueous solution taken in adsorption experiments, and the mass (g) of adsorbent materials used, respectively.…”

“…[ 21 ] The COOH‐GO was synthesized by using GO, which was discussed in our previously reported method. [ 30 ] The novelty of the present work lies in the fact that CMC‐based materials synthesized by ultrasound and microwave‐assisted COOH‐GO‐CMC composites for HTMI removal have been used for the first time. [ 21 ] The synthesis of the composite is easy and eco‐friendly in nature.…”