Graphene oxide based ion-sieving membranes for water purification

Abstract

Graphene oxide (GO), a promising two-dimensional (2D) material, has attracted much attention in membrane filtration techniques such as selective ion filtration and contaminant removal in water treatment. However, its versatility is limited by the fact that GO-based membranes tend to swell when submerged in water. This swelling behaviour will lead to an expansion of the 2D interlayer space, resulting in their inability to block particles in subnano-scale. In this thesis, I studied the modification of GO membrane to fine-tune the 2D interlayer distance and tested the ion-selectivity behaviour of modified GO membrane in lithium ion extraction applications. The impact of functional groups on GO membrane was evaluated by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy measurements. This work will provide a simple strategy in the development of emerging filtering materials for water purification applications.