Adsorption of Heavy Metals by Graphene Oxide/Cellulose Hydrogel Prepared from NaOH/Urea Aqueous Solution

Abstract

By taking advantage of cellulose, graphene oxide (GO), and the process for crosslinking using epichlorohydrin (ECH), we propose a simple and novel method to prepare GO/cellulose hydrogel with good potential to adsorb metal ions. GO nanosheets containing carboxyl and hydroxyl groups were introduced into the surface of the cellulose hydrogel with retention of the gel structure and its nanoporous property. Due to the introduction of GO, the GO/cellulose composite hydrogels exhibited good compressive strength. Adsorption capacity of Cu2+ significantly increases with an increase in the GO/cellulose ratio and GO/cellulose hydrogel showed high adsorption rates. The calculated adsorption capacities at equilibrium (qnormalecal) for GO/cellulose hydrogel (GO:cellulose = 20:100 in weight) was up to 94.34 mg·g−1, which was much higher than that of the pristine cellulose hydrogels. Furthermore, GO/cellulose hydrogel exhibited high efficient regeneration and metal ion recovery, and high adsorption capacity for Zn2+, Fe3+, and Pb2+.

Preparation of cellulose–graphene oxide aerogels with N‐methyl morpholine‐N‐oxide as a solvent

“…On the other hand, the diffraction peak of GO observed around 12° disappeared after mixture with cellulose; this showed the formation of a fully exfoliated structure in the GO sheets in the cellulose substrate . These findings could be explained by the high dispersibility of the GO sheets in the cellulose–GO aerogel, which was due to the bond interactions between GO and the cellulose molecules …”

Natural Polymer Composites for Environmental Applications

“…For example, various functional groups Fig. 3 Cross-linking reaction mechanism of epichlorohydrin (ECH) with graphene oxide (GO) and cellulose [16] (hydroxyl, carboxyl, and epoxy groups) in graphene oxide's extended layered structure ( Fig. 3) provides dispersibility and affinity to many pollutants in water with strong adsorption abilities.…”

Fabrication of a cost-effective lemongrass (Cymbopogon citratus) membrane with antibacterial activity for dye removal

“…However, there was a shi in the intensity of hydroxyl group in the composite membranes of LGES/GO (3340 cm À1 ) and LGDM/GO (3344 cm À1 ) which was attributed to the strong absorption of hydroxyl of GO. 25 The peaks at 2918 cm À1 (LGES, LGDM, LGDM/GO), and 2922 cm À1 (LGES/ GO) were associated to the stretching vibration of the alkane (C-H) group owing to the methyl and methylene group of cellulose. 26 The peak intensity at 1718 cm À1 corresponding to the C]O stretching vibration of -COOH group of GO quite weak in LGES/GO and LGDM/GO composite membrane, which indicated the successful formation of hydrogen bonds with the -OH groups of LGES and LGDM in the composite membrane.…”