Long-lived ¹³⁷Cs/¹³⁴Cs, ⁶⁰Co, and ⁶³Ni with high-energy β/γ emissions are primary toxic fission/activation products in nuclear-contaminated water, causing irreversible damage to the ecological environment and human health. Rapid remediation of these radionuclides emerges as an urgent task, while the deficiencies in adsorption kinetics, selectivity and acid resistance hinder the material innovation for practical applications. Herein, we have developed a hybrid cadmium/tin selenide adsorbent K_3.4(CH₃NH₃)_0.45(NH₄)_0.15Cd₂Sn₃Se₁₀·3.4H₂O (CdSnSe-2K) for the enrichment and sequestration of Cs⁺, Co²⁺, and Ni²⁺ ions. CdSnSe-2K features a unique open-framework constructed from the interlinkage of T2-{M₄Se₁₀} (M = Sn^IV/Cd^II) supertetrahedral clusters and M bridges, accelerating the ion transfer in the tunnel system and thus affording quick kinetics (k₂ = 9.706, 0.182, 0.099 g mg⁻¹ min⁻¹ for Cs⁺, Co²⁺, Ni²⁺). Remarkably, the removal rate R^Cs increases to 98.54% in just 2 min and 99.57% in 5 min (equilibrium), which is responsible for an ultra-high distribution coefficient K_d of 2.31 × 10⁵ mL g⁻¹. The soft-Lewis basic Se component endows CdSnSe-2K with a fantastic adsorption selectivity for Cs⁺, Co²⁺, and Ni²⁺ against various coexisting cations and anions in complex actual water environments even including the highly salty sea water medium. CdSnSe-2K exhibits a fantastic acid/base tolerance over pH = 2–13, and the maximum adsorption capacities q^Cs_m, q^Co_m and q^Ni_m under neutral condition are 218.08 ± 80.08, 43.95 ± 16.57 and 42.53 ± 16.50 mg g⁻¹, respectively. In addition, CdSnSe-2K single crystals were also employed as the stationary phase for the fabrication of an ion exchange column, which shows an elimination efficiency above 99% in the long-term filtration for Cs⁺ (8200 BVs), Co²⁺ (4000 BVs) and Ni²⁺ (4000 BVs). This work not only highlights CdSnSe-2K as a promising Cs⁺, Co²⁺, and Ni²⁺ scavenger in radionuclide remediation, but also provides a supertetrahedral cluster-based construction strategy for open-framework selenide materials with enhanced adsorption kinetics, selectivity, and acid resistance.

中文翻译：

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将超四面体镉/硒化锡簇定制为强大的框架，以有效消除 Cs+、Co2+ 和 Ni2+ 离子

具有高能β/γ排放的长寿命¹³⁷ Cs/ ¹³⁴ Cs、⁶⁰ Co和⁶³ Ni是核污染水中的主要有毒裂变/活化产物，对生态环境和人类健康造成不可逆转的损害。这些放射性核素的快速修复已成为一项紧迫任务，而吸附动力学、选择性和耐酸性方面的缺陷阻碍了实际应用的材料创新。在此，我们开发了一种混合镉/硒化锡吸附剂K _3.4 (CH ₃ NH ₃ ) _0.45 (NH ₄ ) _0.15 Cd ₂ Sn ₃ Se ₁₀ ·3.4H ₂ O ( CdSnSe-2K )，用于富集和封存Cs ⁺、Co ²⁺和Ni ²⁺离子。CdSnSe-2K具有独特的开放式框架，由 T2-{M ₄ Se ₁₀ } (M = Sn ^IV /Cd ^II ) 超四面体团簇和 M 桥互连构成，加速了隧道系统中的离子转移，从而提供快速动力学(对于Cs ⁺、Co ²⁺、Ni ²⁺ ， k ₂ = 9.706, 0.182, 0.099 g mg ^-1 min ^-1 )。值得注意的是，去除率R ^Cs在短短2分钟内增加到98.54%，在5分钟（平衡）内增加到99.57%，这导致了2.31 × 10 ⁵ mL g ^-1的超高分配系数K _d。软路易斯碱性Se组分赋予CdSnSe-2K在复杂的实际水环境中，甚至包括高盐度的海水介质中，对Cs ⁺、Co ²⁺和Ni ²⁺对各种共存的阳离子和阴离子具有优异的吸附选择性。 CdSnSe-2K在 pH = 2–13 范围内表现出优异的酸碱耐受性，中性条件下最大吸附容量q ^Cs _m、q ^Co _m和q ^Ni _m分别为 218.08 ± 80.08、43.95 ± 16.57 和 42.53 ± 16.50 mg g分别为^-1。此外，CdSnSe-2K^{还采用单晶作为固定相制作离子交换柱，对Cs +} (8200 BVs)、Co ²⁺ (4000 BVs)和Ni ^{2 的}长期过滤消除效率均在99%以上⁺（4000 BV）。这项工作不仅凸显了CdSnSe-2K在放射性核素修复中作为一种有前途的 Cs ⁺、Co ²⁺和 Ni ²⁺清除剂，而且还为开放框架硒化物材料提供了一种基于超四面体簇的构建策略，具有增强的吸附动力学、选择性、和耐酸性。