A multifunctional Er-MOF for Methylene Blue adsorption and CO2 cycloaddition catalysis

With the acceleration of industrialization and energy consumption, global concerns for the safety of ecological system and sequent human health have attracted consideration attention increasingly in view of the severe contamination both in aqueous environment and aerosphere. Therefore, the development of multifunctional species for efficient adsorption of pollutants and chemical fixation of CO2 receives increasing attention. Herein, an anionic ErIII metal organic framework (Er-MOF) with large hexagonal channels, is obtained based on a benzene-spaced tetracarboxylate ligand, H4L (H4L = 1,4-bis(2′,2′′,6′,6′′-tetracarboxy-1,4′:4,4′′-pyridyl) benzene). Adsorption analysis indicates that Er-MOF behaves as an excellent adsorbent for selectively absorbing MB in water with a maximum adsorption capacity of 494.1 mg·g‒1. The adsorption mechanism could be a combination of size matching, electrostatic interaction, π···π stacking and hydrogen bonding. In addition, Er-MOF is demonstrated to be an efficient catalyst in the cycloaddition of CO2 with epoxides under mild conditions due to its excellent stability, substantial specific surface area, confined space and well-exposed Lewis acid/base sites. The findings presented herein had great significance for enriching the multifunctional lanthanide MOFs in environmental applications.