Selective Capture of Ba<sup>2+</sup>, Ni<sup>2+</sup>, and Co<sup>2+</sup> by a Robust Layered Metal Sulfide
Yujie Gao, Hai-Yan Sun, Jilong Li, Xing-Hui Qi, Ke‐Zhao Du, Yi-Yu Liao, Xiao‐Ying Huang, Mei‐Ling Feng, Mercouri G. Kanatzidis
Abstract
133Ba, 63Ni, and 60Co are hazardous to the ecosystem and human health. Their nonradioactive isotopes are also worthy of concern as toxic metal ions. Barium can be studied as a simulant of hazardous 226Ra because of their comparable ionic radii and similar ion exchange behaviors. Herein, we report that the layered metal sulfide (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS) exhibits excellent capture properties for Ba2+, Ni2+, and Co2+ with high capacities (qmBa = 289.0 mg/g; qmNi = 83.27 mg/g; and qmCo = 51.98 mg/g), fast kinetics (within 5 min), wide pH durability, and outstanding Ba2+ selectivity. FJSM-SnS exhibits high removal efficiencies (>99%) for these ions in ion-exchange column experiments. The material possesses radiation resistance with good structural and crystal stability; it survives highly acidic conditions. Our results point to a promising scavenger for Ba2+, Ni2+, and Co2+ and, by extension, the even more harmful 226Ra, which suggest that metal sulfide materials should be considered as effective scavengers for these ions from complex wastewater.