Cuprous oxide-loaded AlPO4-5 for highly efficient iodide ions adsorption in chloride molten salt

Developing high-efficiency adsorbent materials for iodide ions in molten salt systems is of great practical significance in nuclear fuel pyroprocessing. In the present work, a cuprous oxide-loaded AlPO4-5 as Cu2O/AlPO4-5 was successfully prepared by copper ammonium complex self-pyrolysis. The adsorption behaviour of Cu2O/AlPO4-5 for iodide ions from chloride molten salt was investigated by a series of static adsorption experiments. It was found that Cu2O/AlPO4-5 exhibited higher iodide ions adsorption capacity (171.63 mg/g) compared with AlPO4-5 (53.49 mg/g) in LiCl–KCl molten salt at 823K, and the adsorption capacity reached the maximum within 2 h. The significant adsorption properties were further proved to mainly result from nanoscale Cu2O particles, which promoted the adsorption material to exhibit chemisorption behaviour, except for the original physisorption. Cu2O/AlPO4-5 also showed adsorption capacity for other ions when anions or cations coexist in molten salt. Our results suggested that aluminophosphate molecular sieves loaded by Cu2O could be applied as adsorbents for radioactive iodide in the molten salt system.