Chitosan-Graphene Oxide Hydrogels with Embedded Magnetic Iron Oxide Nanoparticles for Dye Removal

Abstract

We report a facile design and synthesis of magnetic iron oxide (IO) incorporated chitosan-graphene oxide (CSGO) hydrogel nanocomposites (CSGOIO) by employing in situ mineralization of iron ions in a hydrogel matrix. The mechanism of their formation was investigated by various physical methods, viz., FTIR, XRD, VSM, TGA, SEM, TEM, and BET. This approach was shown to have a direct impact on the morphological features and the structural order of the nanocomposites. The potential of the prepared nanocomposites for effective removal of a cationic dye, methylene blue (MB), from aqueous solution was investigated by performing a series of batch adsorption experiments, in line with the effect of adsorbent dosage, initial dye concentration, contact time, pH, ionic strength, and temperature. The adsorption was fairly influenced by the pH and ionic strength of the medium, indicating an electrostatic interaction between the adsorbent and MB molecules. The kinetics of adsorption followed a pseudo-second-order model, and equilibrium capacity was described by the Freundlich adsorption model. Interestingly, the nanocomposites exhibited a fast removal performance with a rate constant of 0.06 g mg–1 min–1. The hydrogel nanocomposites were found to possess an excellent adsorptive property after four successive cycles at different pH of the solution, thus providing a cost-effective material for dye removal applications. Therefore, this material, enabling dye removal in a wide variety of solution conditions, offered a promising platform for sustainable development of water purification technology.

Target-Specific Superparamagnetic Hydrogel with Excellent pH Sensitivity and Reversibility: A Promising Platform for Biomedical Applications

“…It has important applications in environmental remediation also, such as wastewater treatment, dye adsorption, magnetic separation/bioseparation, etc., where pH plays an important role. 28 pH-sensitive hydrogels are produced by adding an acidic or a basic functional group to the polymer chain; these functional groups either accept or release protons in response to the changes in pH value and ionic strength in the solution and are predominantly responsible to determine the swelling behavior of the hydrogel for a given solution. 29 …”

A green synthesis of nanocatalysts based on reduced graphene oxide/magnetic nanoparticles for the degradation of Acid Red 1

“…[22][23][24][25] Moreover, the presence of magnetic nanoparticles within the structures allows the adsorbed dye to be degraded via the Fenton oxidation process, 26 which in the presence of peroxides without the need for external energy, results in the degradation of dyes via the production of active cOH radicals in the aqueous dye solution. On the other hand, the embedding of magnetic nanoparticles in rGO aerogels result in an improved adsorption efficiency 27 and catalytic performance in the photo-Fenton reaction for the degradation of organic dyes. [28][29][30] For the synthesis of hybrid aerogels based on rGO and magnetic nanoparticles (3D rGO@Fe 3 O 4 NPs), the hydrothermal method is usually employed, which involves a prolonged reaction time (8-20 h) and exposing the reaction mixture to high temperature (180-200 C).…”

Recent Developments in Chitosan-Based Adsorbents for the Removal of Pollutants from Aqueous Environments

“…Magnetic chitosan has emerged as an exciting new material in environmental applications and recently there has been much interest in the applications of magnetic CS/GO [ 164 , 165 ]. The introduction of magnetism facilitates the separation of the adsorbent from the aqueous medium through a simple magnetic process [ 166 ].…”