A Material Design on Radioactive Cesium Adsorbent: Cs_1-xNa_xMn^II(CN)₃ Prussian Blue Analogue

Abstract

After the accident of Fukushima's nuclear power plant, soil contamination was caused by radioactive cesium. In this study, the new cesium-adsorbent: Cs_1-xNa_xMn^II(CN)₃ Prussian blue analogue was theoretically designed to solve the problem. In Prussian blue (iron cyano-compound), both water defect and iron vacancy are closely related to cesium-adsorption. On the other hand, in Cs_1-xNa_xMn^II(CN)₃, the cesium-adsorption mechanism is completely different. Hybrid Kohn-Sham DFT calculations were performed to investigate the cesium-adsorption mechanism. It was concluded that more stable and efficient cesium-adsorption can be realized by the ion exchange between counter cations (between sodium and cesium ions), under applied voltage.