Flower-like Mg/Fe-layered double oxide nanospheres with ultrahigh adsorption efficiency for anionic organic dyes

Flower-like Mg/Fe-layered double oxide (Mg/Fe-LDO) nanospheres were synthesized using a facile one-step hydrothermal method and applied to remove anionic organic dyes, namely, Congo red (CR) and methyl blue (MB) with excellent adsorption efficiency. The Mg/Fe-LDO nanospheres showed over 99% removal efficiency within 25 min and 5 min for CR and MB, respectively. The calculated maximum removal capacities for CR and MB were 1250 mg g-1 and 2000 mg g-1 at 298 K, respectively. The removal of such large quantities of organic dyes was attributed to the chemical adsorption between anionic CR and MB dye molecules and cationic Mg/FeLDO nanospheres through strong electrostatic interactions. Moreover, the reusability test results showed that Mg/Fe-LDO, as an efficient adsorbent, is stable for at least five cycles with over 99% dye removal efficiency. Therefore, it is believed that the excellent dye removal capacities, recycling ability, and facile synthesis of Mg/ Fe-LDO nanospheres will facilitate their practical application in cost-effective wastewater purification.

Automated summary

Flower-like Mg/Fe-layered double oxide (Mg/Fe-LDO) nanospheres were synthesized through a facile one-step hydrothermal method and showed excellent removal efficiency for anionic organic dyes, namely, Congo red (CR) and methyl blue (MB). The high removal capacities for CR and MB, strong chemical adsorption, and good reusability make Mg/Fe-LDO nanospheres a promising candidate for practical application in cost-effective wastewater purification.