Biotemplated self-assembly of ZIF-8 on Vischeria sp. WL1 for efficient uranium removal

Uranium contamination in water poses serious environmental and health risks, necessitating efficient removal technologies. In this study, a novel bio-template strategy was developed to fabricate a high-performance uranium adsorbent. Nitrogen-starved Vischeria sp. WL1 microalgae with reinforced cell walls were used as a support for the in situ growth of ZIF-8, forming a robust composite (V.sp.WL1@ZIF-8). The resulting material exhibited outstanding U(VI) adsorption capacity, with a Langmuir maximum uptake of about 581 mg/g at 298 K. Adsorption kinetics are rapid, reaching equilibrium within 90 min, and fit well with the pseudo-second-order model, suggesting a chemisorption mechanism dominated by surface complexation, with intraparticle diffusion also contributing to the overall rate. Thermodynamic parameters (ΔG < 0, ΔH > 0) confirmed the adsorption process is spontaneous and endothermic, with higher temperatures enhancing capacity. The composite also shows good selectivity in the presence of competing ions (tolerating common cations) and maintains approximately 81 % of its initial capacity after six adsorption–desorption cycles, indicating excellent reusability. These results highlight the performance benefits due to the algae template and ZIF-8 synergy. This work uniquely utilizes nitrogen-starved Vischeria sp. as a robust bio-template for in situ ZIF-8 growth, introducing a novel strategy to enhance MOF–algae integration for uranium remediation. In conclusion, the V.sp.WL1@ZIF-8 composite is a promising and effective material for U(VI) removal from wastewater, offering improved capacity, stability, and potential for practical environmental remediation applications.