Multifunctional La(OH)3@cellulose nanofibrous membranes for efficient oil/water separation and selective removal of dyes

Abstract Water pollution has become a serious problem and water-immiscible oils and water-miscible dyes are two major pollutants. In this work, a multifunctional La(OH)3@cellulose nanofibrous membrane (L-CNM) was prepared through one-pot electrospinning during which the sheet-like La(OH)3 was in situ grown on cellulose nanofibers. The La(OH)3 nanosheets endowed the membrane with a high adsorptive capacity toward Congo red (CR). Interestingly, the obtained membrane was able to not only remove CR from dye mixtures with opposite charges, but also effectively separate CR from dye mixtures having the same charge, which has rarely been reported. Meanwhile, the as-prepared membrane could also separate a series of oil/water mixtures with high fluxes and separation efficiencies due to its underwater superoleophobicity and low oil adhesion. This work may inspire the development of next-generation multifunctional materials for wastewater treatment, especially in selective removal of the target dye from a dye mixture with the same charge.