Capacitive deionization (CDI) is considered one of the most promising desalination technologies for obtaining fresh water from saline water. In this work, we synthesized a hollow core–shell Co-MOF@Fe/Co-LDH (Co-Fe-LDH) material by developing a strategy to simultaneously grow Co/Fe-LDH on the surface of a Co-MOF precursor in situ. Owing to the increase in the specific surface area of the hollow structure and the Faradaic process of a layered double hydroxide (LDH), the Co-Fe-LDH material exhibits high electrical double layer (EDL) capacitance and pseudocapacitance, which significantly improves the salt adsorption of the material during CDI (34.2 mg/g in a 600 mg/L NaCl solution at 1.2 V). The adsorption for NaCl in this work is approximately 2.5 times the maximum salt adsorption capacity (SAC) of LDH materials applied in nonmembrane CDI (NMCDI). This work may provide a promising model for the application of hollow LDH materials that exhibit pseudocapacitance in CDI.

电容去离子（CDI）被认为是从盐水中获得淡水的最有前途的脱盐技术之一。在这项工作中，我们通过制定一种在Co-MOF前驱体表面同时生长Co / Fe-LDH的策略，合成了中空核-壳Co-MOF @ Fe / Co-LDH（Co-Fe-LDH）材料。原地。由于中空结构的比表面积增加以及层状双氢氧化物（LDH）的法拉第过程，Co-Fe-LDH材料显示出高的双电层（EDL）电容和拟电容，从而显着改善了盐分CDI过程中材料的吸附（在1.2 V的600 mg / L NaCl溶液中为34.2 mg / g）。在这项工作中，NaCl的吸附量约为非膜CDI（NMCDI）中使用的LDH材料的最大盐吸附量（SAC）的2.5倍。