Flower-Shaped Mg₃Al 1- x Fe x -CO₃ Layered Double Hydroxides Derived Adsorbents with Tunable Memory Effect for Environmental Remediation.

Herein, flower-shaped ternary layered double hydroxides (LDHs) Mg3Al1-xFex-CO3 with tunable memory effect as promising adsorbents was developed for the removal of acid red 88 anionic dye. All the samples were prepared using a co-precipitation method and were thoroughly characterized using several analytical techniques. The influence of Fe/(Al + Fe) ratio on the memory effect and dye adsorption capacity of Mg3Al1-xFex-CO3 LDHs was evaluated. Among all samples, Mg3Fe0.1Al0.9CO3 LDH resulted in the best adsorption capacity of 2709 mg/g in the first cycle. Comparing to Mg3Al1-CO3 and Mg3Fe1-CO3 LDHs, it also showed much better cycling performance during 4 cycles at 30 °C and atmospheric pressure. The influence of regeneration temperature was also investigated and found that 400 °C exhibit best performance. The detailed studies demonstrated that the adsorption capacity of Mg3Al1-CO3 can be improved by partially replacing Al by Fe.