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Nanographene oxide (nGO) flakes—graphene oxide with a lateral size of ≈100 nm or less—hold great promise for superior flux and energy‐efficient nanofiltration membranes for desalination and precise ionic sieving owing to their unique high‐density water channels with less tortuousness. However, their potential usage is currently limited by several challenges, including the tricky self‐assembly of nano‐sized flakes on substrates with micron‐sized pores, severe swelling in aqueous solutions, and mechanical instability. Herein, the successful fabrication of a robust membrane stacked with nGO flakes on a substrate with a pore size of 0.22 µm by vacuum filtration is reported. This membrane achieved an unprecedented water permeance above 819.1 LMH bar−1, with a high rejection rate of 99.7% for multivalent metal ions. The nGO flakes prepared using an electron beam irradiation method, have uniquely pure hydroxyl groups and abundant aromatic regions. The calculations revealed the strong hydrogen bonds between two nGO flakes, which arise from hydroxyl groups, coupled with hydrophobic aromatic regions, greatly enhance the stability of stacked flakes in aqueous solutions and increase their effective lateral size. The research presents a simple yet effective approach toward the fabrication of advanced 2D nanographene membranes with superior performance for ion sieving applications. [ABSTRACT FROM AUTHOR]

Functional nanoscale structures consisting of a DNA molecule coupled to graphene or graphene oxide (GO) have great potential for applications in biosensors, biomedicine, nanotechnology, and materials science. Extensive studies using the most sophisticated experimental techniques and theoretical methods have still not clarified the dynamic process of single-stranded DNA (ssDNA) adsorbed on GO surfaces. Based on a molecular dynamics simulation, this work shows that an ssDNA segment could be stably adsorbed on a GO surface through hydrogen bonding and π-π stacking interactions, with preferential binding to the oxidized rather than to the unoxidized region of the GO surface. The adsorption process shows a dynamic cooperation adsorption behavior; the ssDNA segment first captures the oxidized groups of the GO surface by hydrogen bonding interaction, and then the configuration relaxes to maximize the π-π stacking interactions between the aromatic rings of the nucleobases and those of the GO surface. We attributed this behavior to the faster forming hydrogen bonding interaction compared to π-π stacking; the π-π stacking interaction needs more relaxation time to regulate the configuration of the ssDNA segment to fit the aromatic rings on the GO surface. [ABSTRACT FROM AUTHOR]