Zr-doped MIL-101(Fe)/Graphene oxide nanocomposites: An efficient and water-stable MOF-based adsorbent for As(V) adsorption in aqueous solution

Eliminating arsenic contaminants has become an imperative issue due to its persistent and serious harm to the environment and human health. Herein, a novel FeZr-MOFs/GO nanocomposite for effectively removing As(V) was fabricated by growing Fe-based metal–organic frameworks (Fe-MOFs) of MIL-101(Fe) on the graphene oxide (GO) surface with the addition of Zr(IV) dopants. The presence of GO, the doping amount of Zr ions, and the functional groups of the ligands were found to have an impact on the adsorption performance of Fe-MOFs. Notably, doping an appropriate amount of Zr(IV) resulted in a significant increase in water stability of MIL-101(Fe) and MIL-101(Fe)/GO nanocomposites. This improvement, along with chemical complexation and hydrogen bonding, played a pivotal role in the adsorption of As(V). The optimized FeZr-MOFs-0.2/GO (0.2 represented the molar ratio between Zr and Fe) nanocomposites demonstrated superior As(V) adsorption performance with an adsorption capacity of up to 91.69 mg·g−1. Moreover, this system proven effective across a wide range of pH (2–10) and environmental matrices. This study not only provides attractive MOF nanocomposites for broadening the application of aqueous solutions, but also opens up a novel avenue for the rational design and development of nanocomposites with exceptional properties and stability.