In-situ nanoparticles intercalating graphene oxide membranes for superior water transport in dye desalination

Graphene oxide (GO) membrane has been considered as a promising approach for harvesting pure water from various wastewater to deal with the current water shortage issue, arising from its distinctive 2D channel features. However, the narrow interlayer distance (0.75 Å) of GO nanosheets hampers the utilization of GO membranes for dye wastewater treatment, which demands superior water permeance, high dyes rejection, and low salts rejection. Herein, an in-situ anchored nanoparticle strategy is designed to fabricate Fe(OH)3@GO membrane to enlarge the interlayer distance via the uniform distributed Fe(OH)3 nanoparticles. Benefiting from the in-situ transformation of Fe3+ into positively charged Fe(OH)3 nanoparticles, the interlayer distance of GO membranes can be tailored via changing the Fe: GO mass ratio and hydrolysis time. The optimized Fe(OH)3@GO membrane realizes a superior water permeance of ∼90.9 LMH/bar (∼19-fold enhancement compared with GO membranes), with >99% and <4% rejection to Evans blue (EB) and NaCl, respectively. Thus, the membrane can be applied for dye desalination and can be stably running for 85 h. Considering the facile and efficient 2D channel tunability, our strategy provides an innovative approach for construction of high-performance 2D membranes.