Synthesis of NZVI@MOF composite for efficient U(VI) removal from aqueous solution

An NZVI@MOF composite was synthesized via liquid-phase reduction and ambient-temperature precipitation, which not only mitigates NZVI agglomeration but also significantly increases the active sites. Under optimized conditions (pH = 6.0, initial U(VI) concentration of 80 mg L −1 ), the as-synthesized NZVI@MOF composite achieved a maximum adsorption capacity of 349 mg g −1 and a removal efficiency of 96%, outperforming pristine NZVI, MOFs, and conventional adsorbents (e.g., zeolites and activated carbon) via an “adsorption-reduction” synergistic mechanism. Kinetic studies revealed that the adsorption conforms to a pseudo-second-order model, while the Freundlich isotherm model indicated a heterogeneous multilayer chemisorption mechanism. These findings highlight the NZVI@MOF composite as a promising material for radioactive wastewater treatment.