Graphene oxide–chitosan composite hydrogels as broad-spectrum adsorbents for water purification

Abstract

Water pollution is one of the most pervasive problems afflicting people throughout the world, while adsorption is the most widely used method to remove the contaminants from water. Here, in this paper, we report an eco-friendly graphene oxide-chitosan (GO-CS) hydrogel as a new type of adsorbent for water purification. The GO-CS hydrogels were prepared via self-assembly of GO sheets and CS chains. A three-dimensional network composed of GO sheets crosslinked by CS was found in GO-CS hydrogels.The GO-CS composite hydrogels showed high adsorption capacity towards different contaminants, including cationic and anionic dyes, as well as heavy metal ions. The mechanism of the dye adsorption was investigated with a spectral method, and an electrostatic interaction was found to be the major interaction between ionic dyes and the hydrogel. The influence of the hydrogel composition on the adsorption capacity towards different adsorbates was also studied. Finally, it was demonstrated that the GO-CS hydrogel can be used as column packing, to fabricate a column for water purification by filtration.

One Pot Synthesis of Nickel Nanoparticles Stabilized on rGO/Polyethyleneimine Aerogel for the Catalytic Hydrogen Generation

“…The SEM image of NiNPs@rGO-bPEI aerogel (bPEI/ GO = 4) shows a plastic-like form (Fig. 4e, f) [59][60][61]. The TEM images of NiNPs@rGO-bPEI aerogel indicates the successful dispersion of Ni nanoparticles with the size of 18-20 nm on the surface of the rGO-based aerogel (Fig.…”

Activated Carbon, Carbon Nanotubes and Graphene: Materials and Composites for Advanced Water Purification

“…Chitosan has been used with GO to prepare adsorbent hydrogel materials that have affinities for both cationic and anionic dyes, as well as heavy metals. The adsorption capacities of the dyes methylene blue and Eosin Y were reported as greater than 300 mg/g, while the adsorption of Cu(II) and Pb(II) were found to be 70 and 90 mg/g respectively [187]. A more complex material for the adsorption of Pb(II) has been realized by the combination of magnetic chitosan and GO that was imprinted with Pb(II) ions.…”

Magnetic ZnFe2O4@chitosan encapsulated in graphene oxide for adsorptive removal of organic dye

“…10 Chen et al studied the application of graphene oxidechitosan (GO-CS) composite hydrogels for the removal of organic dyes and found that the GO-CS composites showed maximal adsorption capacities towards cationic MB and anionic eosin Y with values of both being higher than 300 mg g À1 . 11 Recently, magnetic nanoparticle loaded adsorbent materials have been the subject of extensive attention because of their gentle operating conditions, easily manipulated process and high separation efficiency.…”