Synergistic redox adsorption of multiple iodine species by a Cu0-anchored Mn-Cu carbon composite

Radioactive iodine ( 131 I and 129 I) produced by the development of nuclear energy poses a long-term threat to ecology and health. In this study, a series of Cu@Mn x Cu 10-x -C materials were synthesized using Mn x Cu 10-x -BTC as the precursor, followed by surface grinding with external copper salts and subsequent pyrolysis. The material achieved a uniform dispersion of high-density Cu 0 sites on the Mn-Cu carbon framework. The optimal material Cu@Mn 3 Cu 7 -C had saturated adsorption capacities of 346.6 mg/g and 1555.3 mg/g for iodide (I − ) and iodine (I 2 ) respectively, further improving under acidic and oxygen-rich conditions. In addition, it could maintain excellent I − adsorption performance in the presence of highly competitive anions, in actual water samples, and after high-dose γ-irradiation. Mechanism studies demonstrated that Cu 0 , as the reaction center, dominated the oxidation-adsorption of I − and the reduction and fixation of I 2 , while triiodide (I 3 − ) could be effectively eliminated through the [Cu → I 3 ] charge transfer complexation or disproportionation pathway. The Mn species cooperated with the Cu site through valence modulation and electron transfer. This study provides a material system and theoretical basis for the efficient removal of multiple iodine species in complex water bodies with high capacity, fast kinetics and good environmental adaptability.