Performance and Mechanism of Layered Double Hydroxide to Remove Graphene Oxide in Aqueous Solution

摘要

Intending to remove toxic graphene oxide (GO) from wastewater, LDH (layered double hydroxide) was employed to recover GO by adsorption method. The adsorption performance and the mechanism of LDH for GO have been systematically studied by diverse characterization technologies and methods. The relevant effects of solution pH (2-9), absorbent dosage (5-25mg) and the concentration of GO (20-160mg/L) were investigated in detail. The main driving force of GO condensation on LDH may be electrostatic interaction and hydrogen bonding, SEM, TEM, AFM, FT-IR and XRD analysis further confirmed this. XPS test shows that the adsorption process is carried out through C?O and O?C=O. We have got a high removal rate of 92% and an adsorption capacity of 1472 mg/g under an optimized conditions (pH = 3.0, equilibrium time = 6.0 h, dosage = 10mg, C0 = 160 mg/L). The analyses implied that LDH will be a very promising candidate for recovery of GO from wastewater.