Boron nitride nanosheets filtration membrane for efficient separation of pollutant molecules from aqueous solution

Abstract

Two dimensional nanomaterials have exhibit promising performance in membrane science, especially hexagonal boron nitride nanosheets (BNNSs) with inherent chemical inertness. Here, BNNSs membranes with compact and well-organized stacking texture were successfully prepared via vacuum-assisted filtration approach using chemo-mechanical exfoliated and functionalized BNNSs as matrix. The BNNSs with an average lateral dimension of ~100 nm have few layers structure and abundant hydroxyl and amino groups. The viscosity of the solvent and thickness of membrane are important factors affecting the permeability performance. Importantly, the BNNSs membranes exhibit fascinating filtration and separation performance for various pollutants in water, including abusive organic dyes, heavy metal ion and drugs. Specifically, the membrane with a typical thickness of 30 μm shows the water flux up to 2.1 L⋅m −2 ⋅min −1 ⋅bar −1 and 99.87% removal rate for tetracycline. These performances are not only caused by simple physical interception of BNNSs constructed nanochannels, but also by certain intermolecular chemical interactions between functional groups on BNNSs and pollutant molecules. This work would provide experimental foundation and analytical experience for the practical application of BNNSs membranes in the field of complex water purification.