Graphene oxide membranes tuned by metal-phytic acid coordination complex for butanol dehydration

For two-dimensional (2D) lamellar graphene oxide (GO) membranes, tuning the interlayer distance and enhancing surface hydrophilicity are two efficient strategies to achieve high selectivity and permeation flux for solvent dehydration. Herein, Fe3+-phytic acid (PA) coordination complex was designed as both the intercalator and surface modifier to fabricate hydrophilic GO membranes. Fe3+-PA complexes interacted with the oxygen-containing functional groups of GO nanosheets through non-covalent interactions to fix the interlayer distances to 0.61 nm in 90 wt% n-butanol/water mixture. Moreover, Fe3+-PA complexes enhanced the surface hydrophilicity of GO membranes, which promoted the water sorption ability of the membrane and facilitated the fast water-transport. The pervaporation n-butanol dehydration performance was investigated as a function of Fe3+-PA complex content and feed temperature. GO-PA-Fe3+/PTFE membranes with an optimized PA addition amount of 50 wt% exhibited a separation factor of 1059 and a permeation flux of 10.57 kg/(m2 h) under 80 °C for 90 wt% n-butanol/water mixture. This study provides a novel avenue to fabricating 2D lamellar separation membranes by incorporating multifunctional metal-coordinated complexes.