Hybrid graphene oxide membranes with regulated water and ion permeation channels via functional materials

Graphene oxide is a two-dimensional (2D) material with rich surface functionality that has demonstrated great potential to develop membranes with adaptive water and ion permeation channels. Inspired by natural cell membranes, stimuliresponsive hybrid graphene oxide membranes (GOMs) with controlled permeation channels are fabricated by smart functionalization of 2D nanocapillaries using functional molecules. Highly selective GOMs with good structural stability can be achieved by intercalating crosslinking agents or in-situ growth of nanoparticles in the interlayer spacing. This short review first highlights the recent breakthrough in the design and fabrication of stimuli-responsive GOMs, focusing on the water separation performance and water and solute (ion) permeation mechanisms under different external conditions. The second part underlines different methods of crosslinking and nanoparticles intercalation to improve the size-sieving ability of GOMs. Finally, the permeation mechanism, future challenges, and perspectives will be discussed briefly.