Research progress on structural tuning and heavy metal ion adsorption of layered double hydroxides

Layered double hydroxides (LDHs) are anionic clays with special layered structure and have attracted much attention in wastewater treatment due to their adjustable chemical composition, large specific surface area and unique structural memory effect. Structure tuning of LDH, is an effective way to further expand their application range and improve their adsorption performance. In this review, the special layered structure of LDHs and their own properties were introduced, followed by summarization on the five most commonly used LDH preparation methods, namely co-precipitation, ion exchange, urea hydrolysis, calcination recovery and sol-gel method, and the principles and characteristics of each preparation method. The influence of LDH structural tuning on their adsorption performance for heavy metal ions were then reviewed, and the adsorption mechanism on heavy metal ions was further summarized. Finally, the current challenges of LDH for the removal of heavy metal ion from wastewater were discussed, and the future research directions and development trends were prospected. © 2024 Fine Chemicals. All rights reserved.