Chitosan-Cross-Linked Graphene Oxide/Carboxymethyl Cellulose Aerogel Globules with High Structure Stability in Liquid and Extremely High Adsorption Ability

Abstract

Graphene oxide (GO) exhibits excellent adsorption ability to remove organic dyes from liquid; therefore, fabricating GO-based adsorbents has attracted increasing interest from researchers. However, it is still challenging to prepare the GO-based adsorbents with high structure stability while simultaneously maintaining its high adsorption ability. In this work, a novel one-step fabrication method combining exfoliating and micro-cross-linking simultaneously was proposed to prepare the GO composite aerogel globules, in which GO was exfoliated by carboxymethyl cellulose (CMC) in the globule center, whereas the globule was micro-cross-linked by chitosan (CS) on the surface. The results showed that there were strong interactions between components, and the composite aerogel globule exhibited multiscale porous structures on the globule surface and the highly porous structure in the globule center. The composite aerogel exhibited high structure stability in liquid. The adsorption measurements toward methylene blue (MB) showed that the CS-GO/CMC composite aerogel had extremely high adsorption capacity, and the maximum adsorption capacity was 3190 mg/g for the CS-GO/CMC-1/1 composite aerogel, which was the highest adsorption capacity reported in the literature. The adsorption kinetics, adsorption isotherms, and the adsorption thermodynamics were comparatively investigated. The results showed that the adsorption of MB obeyed a pseudo-second-order model and Langmuir adsorption model, and the adsorption was a spontaneous process. Furthermore, the composite aerogel also showed excellent removal ability for Cr­(VI), and the adsorption capacity was 127.4 mg/g. The extremely high adsorption abilities toward MB and Cr­(VI) and high structural stability in liquid endow the CS-GO/CMC composite aerogel with potential applications in wastewater treatment.

Synthesis, characterization, morphology, and adsorption studies of ternary nanocomposite comprising graphene oxide, chitosan, and polypyrrole

“…However, the bands arising at 1500 and 1680 cm −1 may be attributed to the amide I vibrations. [ 17 ] Similarly, in the PPy spectrum the bands appearing at 1590 and 1400 cm −1 are diagnostic to the fundamental vibrations of PPy rings whereas the bands observed at 1050 and 910 cm −1 may be regarded due to the CH in‐plane vibrations, and to the CN stretching vibrations, respectively. [ 34 ]…”

Directionally-Grown Carboxymethyl Cellulose/Reduced Graphene Oxide Aerogel with Excellent Structure Stability and Adsorption Capacity

“…GO as the active adsorption sites provided an advantageous condition for attracting more MB molecules and consequently improved the rate of adsorption capacities in theory. Moreover, the ion exchange process, hydrogen bonding, π–π interaction and electrostatic interaction [ 19 , 39 , 40 ] of L-CMC/rGO aerogel and MB molecules are also responsible for the MB removal.…”

Graphene‐Based Macromolecular Assemblies for Scavenging Heavy Metals

“…Apart from sponges, spheroidal scaffolds with hierarchical porous structures have also been proposed in recent years, to effectively separate heavy metal ions from contaminated waters [66,67] . For instance, Yu et al [66] .…”