State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
Environ Sci Technol. 2023 Apr 18;57(15):6342-6352. doi: 10.1021/acs.est.2c09683. Epub 2023 Apr 3.
Selective removal of trace, highly toxic arsenic from water is vital to ensure an adequate and safe drinking water supply for over 230 million people around the globe affected by arsenic contamination. Here, we developed an Fe-based metal-organic framework (MOF) with a ferrocene (Fc) redox-active bridge (termed Fe-MIL-88B-Fc) for the highly selective removal of As(III) from water. At a cell voltage of 1.2 V, Fe-MIL-88B-Fc can selectively separate and oxidize As(III) into the less harmful As(V) state in the presence of a 100- to 1250-fold excess of competing electrolyte, with an uptake capacity of >110 mg-As g adsorbent. The high affinity between the uncharged As(III) and the μ-O trimer (-36.55 kcal mol) in Fe-MIL-88B-Fc and the electron transfer between As(III) and redox-active Fc synergistically govern the selective capture and conversion of arsenic. The Fe-based MOF demonstrates high selectivity and capacity to remediate arsenic-contaminated natural water at a low energy cost (0.025 kWh m). This study provides valuable guidance for the tailoring of effective and robust electrodes, which can lead to a wider application of electrochemical separation technologies.
从水中选择性去除痕量、剧毒的砷对于确保全球 2.3 亿多名受砷污染影响的人获得充足和安全的饮用水至关重要。在这里，我们开发了一种具有二茂铁（Fc）氧化还原活性桥的基于铁的金属-有机骨架（MOF）（称为 Fe-MIL-88B-Fc），用于从水中高度选择性地去除 As(III)。在 1.2 V 的电池电压下，Fe-MIL-88B-Fc 可以在存在 100-1250 倍过量的竞争电解质的情况下选择性地分离和氧化 As(III)为毒性较小的 As(V)状态，其摄取容量> 110 mg-As g 吸附剂。未带电的 As(III)与 Fe-MIL-88B-Fc 中的μ-O 三聚体（-36.55 kcal mol）之间的高亲和力以及 As(III)和氧化还原活性 Fc 之间的电子转移协同控制砷的选择性捕获和转化。该基于铁的 MOF 以低能耗（0.025 kWh m）表现出对受砷污染的天然水进行修复的高选择性和容量。这项研究为定制有效和强大的电极提供了有价值的指导，这将导致电化学分离技术的更广泛应用。
