3D/2D MnO/MXene heterostructure with high efficiency for adsorbing uranium

An innovative MnO/Ti 3 C 2 MXene heterostructure, consisting of three-dimensional (3D) MnO nanosheet array directly assembled on two-dimensional (2D) Ti 3 C 2 MXene nanosheets, was synthesized via a simple hydrothermal-annealing strategy for uranium elimination. This unique 3D/2D heterostructure derived substantially high specific surface area (311.9 m 2 /g) and exposed considerable amount of surface oxygen groups, including surface lattice M–O and adsorbed –OH. Through a comprehensive exploration encompassing adsorbent dosage, pH, ionic strength, initial U(VI) concentration, and environmental conditions, the MnO/Ti 3 C 2 MXene heterostructure demonstrated an extraordinary proficiency and specificity in the removal of U(VI). This composite exhibited an outstanding adsorption capacity of 862.1 mg/g, with a removal efficiency of 99.7 % and rapid kinetics (above 90 % within 20 s). The kinetic study indicated the adsorption process followed chemisorption dynamics and single-layer adsorption behavior. Comprehensive analyses validated the structural integrity and confirmed the successful uranium adsorption via strong interaction between UO 2 2+ and surface unsaturated oxygen groups. Notably, the MnO/Ti 3 C 2 MXene maintained excellent recyclability, highlighting its potential for large-scale applications. It emerges as a promising candidate for uranium removal, offering insights for optimizing composite materials in diverse environmental conditions and fostering advancements in water purification technologies.