Highly effective prussian blue-coated MXene aerogel spheres for selective removal of cesium ions

Two-dimensional titanium carbide MXene (Ti₃C₂T_x) incorporated with Prussian blue aerogel spheres (PBMX_sphere) were designed and fabricated by a simple synthesis method for selective cesium removal in different matrices. The synthesized micro spheres exhibited unique internal structure and high porosity. They were enriched with oxygenated functional groups of Ti₃C₂T_x and offered selective binding sites of Prussian blue. The synthesized PBMX_sphere can thus be used as a unique adsorbent for radionuclide Cs⁺ removal in water. Analytical techniques such as PXRD, FT-IR, FE-SEM, and XPS were utilized to investigate the material characteristics and structural changes after cesium ion adsorption. The PBMX_sphere spheres unveiled an exceptional adsorption capacity of 315.91 mg/g for Cs⁺, which is amongst the highest values reported for similar adsorbents. PBMX-III_sphere was capable for removing cesium ions at the ppb level with a distribution coefficient of 3.42 × 10⁰⁵ mL/g in the presence of coexisting ions such as Na⁺, K⁺, Mg²⁺, and Ca²⁺. The PBMX_sphere spheres were highly efficient for Cs⁺ removal under extreme pH values (pH 2–12). Furthermore, PBMX-III_sphere offered exceptionally high removal efficiency in 1 M HCl and 5 M NaNO₃ solution matrices. For practical applications, extraordinary Cs⁺ capturing behavior was observed in simulated seawater.