Recent progress on highly efficient removal of heavy metals by layered double hydroxides

With the development of industry and agriculture, heavy metals cause serious pollution to water resources and soil, and it is very urgent to develop highly efficient and low-cost heavy metals removal materials. Due to their low Ksp, super-stable mineralization effect, easily modified surfaces, and anion intercalation properties, layered double hydroxides (LDHs) exhibit unique advantages in heavy metal ion removal. It is very important to clarify the removal mechanism of heavy metal ions by LDHs for the subsequent structure design of adsorbent. Herein, according to the unique layered structure of LDHs, we summarized recent progress of LDHs for heavy metals uptake from the following aspects: 1) Based on the tunability and modifiability of the LDHs laminate, we summarized the application of LDHs in removing heavy metals through the super-stable mineralization effect and coordination adsorption mechanism; 2) Based on the flexibility of anions in the interlayer of LDHs, we reviewed heavy metals removal by LDHs from anion intercalation and interlayer coordination perspective.