Cu2+‐doped ZIF-8 derived nitrogen-carbon anchored Cu0 particles for highly efficient iodide elimination

Radioactive iodine (I) produced in the nuclear industry can be eliminated through solid-phase adsorption. Nevertheless, conventional adsorbents suffer from limited capacity, poor selectivity, and insufficient stability. In this study, metallic copper modified nitrogen-doped carbon composites (Cu x -NC) were prepared from a pre-synthesized template of Cu 2+ -zeolite imidazole framework-8 (Cu 2+ -ZIF-8) by ball milling combined with pyrolysis processes. The surface physical and chemical properties of Cu x -NC composites were characterized, and then applied to remove iodide (I - ) in aqueous solutions. The experimental results indicated that Cu 0 introduced to nitrogen-doped carbon not only significantly enhanced I - removal but also achieved an exceptional adsorption capacity of 269.2 mg/g by incorporating 35 % copper and setting the pyrolysis temperature at 1000 °C. Notably, under acidic (pH = 3) and blown air conditions, the adsorption capacity was markedly increased, attaining 383.3 and 474.3 mg/g, respectively. The Cu 35 -NC demonstrated exceptional selectivity for I - in the presence of interfering anions such as Cl - and SO 4 2- . Mechanism studies showed that as-fabricated materials eliminated I - through adsorption and oxidation. The presence of Cu 0 particles activated molecular oxygen to release Cu + and generate H 2 O 2 , resulting in I - being adsorbed and oxidized. These findings underscore the significant potential of the economical Cu x -NC for the effective elimination of radioactive iodide.