Efficient uranium(VI) separation based on a layered 2D Ti3C2Tx/hydroxyapatite hybrid membrane

Lamellar membranes made from 2D materials have garnered significant attention as advanced separation materials for wastewater treatment, particularly for wastewater containing uranium (U(VI)). Nevertheless, it is still a great challenge to obtain assembled lamellar membranes with both high flux and retention rate from 2D materials. In this work, a method of in-situ loading hydroxyapatite nanoparticles onto MXene nanosheets and vacuum filtration to form a novel Ti₃C₂T_x MXene/hydroxyapatite (MXene/HAP, MXHP) membrane had been developed for separating U(VI) from wastewater. From the characterization results, the MXHP membrane displayed an increasing trend of interfacial pores and interlayer channels for comparison to the pure MXene membrane, which could notably improve water permeability of MXHP membrane. Based on membrane separation experiments, the MXHP-2 membrane achieved a flux of 515.5 L/(m²·h·bar) and a U(VI) retention rate of 98.2 % in the treatment of U(VI)-containing wastewater. Additionally, the MXHP-2 membrane exhibited strong recyclability with a high U(VI) retention rate of 85.3 % after five cycles. The U(VI) separation mechanism of MXHP-2 was photocatalytic reduction assisted dissolution-deposition. The above results could provide valuable insights for developing new composite membranes with high throughput and high uranium retention rate.