Ti₃C₂T_x MXene core-shell spheres for ultrahigh removal of mercuric ions

Two-dimensional (2-D) titanium carbide MXene core (Ti₃C₂T_x) shell aerogel spheres (MX-SA) for mercuric ion removal were designed and fabricated with varying concentrations of Ti₃C₂T_x MXene and sodium alginate (SA) using a facile method. Owing to their unique inside structures, high porosities, large specific surface areas, oxygenated functional groups of MXene nanosheets, and available active binding sites, the synthesized microspheres constitute a unique adsorbent for heavy metals removal in water. The MX-SA_4:20 spheres exhibit an exceptional adsorption capacity of 932.84 mg/g for Hg²⁺, which is among the highest value reported for adsorbents. The adsorbent exhibits high single- and multi-component removal efficiencies, with 100% efficiency for Hg²⁺ and >90% efficiency for five heavy metal ions. The synthesized materials are highly efficient for Hg²⁺ removal under extreme pH conditions (0.5–1.0 M HNO₃) and have additional excellent reproducible properties. The micro-size and spherical shape of MX-SA_4:20 also allow it to be used in column-packed devices.