Title
Hydrothermally Reduced Graphene Hydrogel Intercalated withDivalent Ions for Dye Adsorption Studies
Author
Alvin Lim Terik Zheng
Year
2021
Journal
MDPI
Abstract
Fundamental studies involving divalent ion intercalated graphene-based hydrogel are stilllacking in terms of their adsorption behavior towards dye pollutants. In this study, we prepared aself-assembled Mg2+and Ca2+intercalated reduced graphene hydrogel (rGH) using hydrothermaltreatment to evaluate the intercalation impact on the adsorption capability towards cationic dyes,methylene blue and rhodamine B. The morphological, structural, thermal, and textural propertiesof the divalent ion intercalated reduced graphene hydrogels were studied using Fourier trans-form infrared spectrometer, thermogravimetric analysis, Raman spectroscopy, scanning electronmicroscope-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface area analysis, and X-ray diffraction. The increased adsorption capacity of the divalention intercalated reduced graphene-based hydrogels towards the dye molecules resulted from theincrease in the specific surface area and pore volume due to the Mg2+and Ca2+bridging that formedspaces between the graphene sheets framework. Adsorption kinetics and the equilibrium adsorptionisotherm were fitted by a pseudo-second-order alongside intraparticle diffusion kinetic models andLangmuir isotherm respectively. In addition, the divalent ion intercalated reduced graphene hydrogelshowed good generation after three cycles of simultaneous adsorption
Instrument
NRS-5100
Keywords
graphene hydrogel; hydrothermal; dye adsorption; calcium; magnesium