Hollow Mesoporous Titanate via Self-Sacrificed Template for Dramatically Enhanced Elimination of Uranium from Aqueous Solution

U(VI) has emerged as a significant environmental contaminant, with its profound and irreversible effects on the surrounding ecosystem. Titanate and their derivatives have garnered considerable attention due to their exceptional ion-exchange capabilities, strong attraction to heavy metal ions, and high level of activity. In this work, we have described a straightforward and cost-effective process for producing uniform titanate (K2Ti4O9) hollow mesoporous spheres. The surface roughness and hollow structure of Hollow mesoporous titanate (MKTO) were found to be advantageous for capturing U(VI) at an impressive capability in excess of 235 mg/g. The kinetic and isothermal characteristics were appropriate for describing the pseudo-first-order model and Freundlich model, respectively. The adsorption mechanism was thoroughly explained and visualized through spectral analysis, revealing a distinct cation exchange occurring between interlayered K+ and UO22+ and U(VI) consumption selectivity determined by metal–oxygen sites of MKTO through complexation. The adsorption capacity only decreased from 61.4% to 59.0% after five cycles, indicating a favorable recycling performance. Due to its remarkable ion-exchange capacity and easy synthesis process, MKTO materials showed great promise for efficiently removing U(VI) from water-based solutions to address environmental radioactive contamination.