Fenton induced microdefects enable fast water transfer of graphene oxide membrane for efficient water purification

Recent studies have highlighted the great potential of graphene oxide (GO) as the basis of advanced separation membranes for water-related environmental applications. However, pristine GO membranes usually suffer from low water permeability and inadequate stability that limit their further progress and application in practice. Here, a novel approach involving intra-defect construction, combined with cation cross-linking, was used to prepare highly permeable and stable GO membranes for water purification. The preparation was based on Fenton system to achieve enhanced regulation of the membrane structure. The in-situ generated Fe(III) and reaction products (hydroxyl radical and Fe-based nanoparticles) enabled the formation of tightly cross-linked GO nanosheets and favorable pinholes and void defects within the membrane, which stabilized the membrane structure and enhanced its permeability. The resultant membrane achieved an ultrahigh water flux (∼45 L m⁻² h⁻¹ bar⁻¹), together with a favorable rejection of Coomassie brilliant blue dye (>91%), natural organic matter (humic acid and bovine serum albumin, >95%) and superior dye/salt selectivity. Moreover, the membrane exhibited a long-term operating stability and pressure-resistance performance. This study offers a facile and scalable method for the design of high performance GO and other two-dimensional (2D) membranes for water purification.