Highly robust and efficient dye rejection enabled by rGO/MXene heterogeneous membranes

Abstract

Graphene oxide (GO) membranes are limited by inherent structural instability and relatively low permeability in aqueous environments, which hinder their practical application in waste water treatment. To address these challenges, we engineered heterogeneous membranes by incorporating MXene nanosheets into a reduced graphene oxide (rGO) framework, leveraging the complementary properties of these two two-dimensional materials to enhance both structural stability and water transport channels. The resulting rGO/MXene heterogeneous membranes achieved an exceptional separation performance, with the highest water permeance of up to 401.2 L m⁻² h⁻¹ bar⁻¹ while retaining 99.7% rejection of dye molecules. The water permeance was 2.4 times greater than that of pristine rGO membranes and competitively surpassed that of most advanced nanofiltration (NF) membranes reported for dye wastewater treatment. More importantly, the rGO/MXene heterogeneous membranes exhibited outstanding mechanical robustness in demanding filtration environments. Notably, the membrane retained structural integrity after 50 deformation cycles (stretching/bending) under hydrated conditions. Additionally, rGO/MXene heterogeneous membranes showed good antifouling performance. Overall, these findings indicate the strong potential of these new materials as durable and high-efficiency separation material membranes for industrial water-treatment applications.