Two-dimensional (2-D) titanium carbide MXene core (Ti3C2Tx) shell aerogel spheres (MX-SA) for mercuric ion removal were designed and fabricated with varying concentrations of Ti3C2Tx 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-SA4:20 spheres exhibit an exceptional adsorption capacity of 2+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-SA4:20 also allow it to be used in column-packed devices.