Membrane separation technology has become one of the most effective methods for water treatment, owing to its advantages of high separation efficiency, convenient operation and low-energy consumption. The membranes prepared from graphene oxide (GO) have received extensive attention for their high water permeability which is attributable to rapid water transport in the atomically smooth sp2 regions (non-oxidized regions) of their membrane channels.
This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility: Credit: Higher Education Press Limited Company Reduced graphene oxide (RGO) membranes are theoretically more conducive to the rapid transport of water molecules in their channels compared with graphene oxide (GO) membranes, as they have fewer oxygen-containing functional groups and more non-oxidized regions. However, experimental results from literature indicated that the RGO membranes generally show very low water permeabilities, even lower than 1.0 L/(m2·h·bar). The reduction process of GO to RGO can decrease the number of oxygen functional groups on RGO nanosheets, thus, RGO membranes exhibit weaker hydrophilicity and narrower interlayer spacing. Despite rapid transport of water molecules in the non-oxidized regions of RGO membrane channels, their weakly hydrophilic and narrow membrane channels could hamper the entry of water molecules into the channels, resulting in lower water permeability. In addition, the reduction of oxygen functional groups on the RGO membrane surface would weaken the electrostatic interactions between the membrane…