Base-functionalized metal−organic frameworks for highly efficient removal of organic acid pollutants from water.

Organic acid contaminated wastewater has been of great concerns for water recovery. Base-functionalized metal−organic framework DETA-UiO-66 by grafting diethylenetriamine onto UiO-66 achieved remarkable H 2 -FA capacity with large adsorption rate compared with parent UiO-66 and sulfonate-functionalized SO 3 H-UiO-66. According to the adsorption behavior at various p Hs, an adsorption mechanism was proposed involving the acid–base interaction and weak electrostatic interaction. Further investigation including adsorption kinetics, isotherms, thermodynamics, demonstrated that the H 2 -FA adsorption process on DETA-UiO-66 was a spontaneous exothermic process with a theoretical adsorption capacity reaching up to 561.8 mg g−1 at 10 °C. In addition, DETA-UiO-66 can be recovered through simple ethanol washing and reused for at least three times, remaining high adsorption capacity and adsorption rate. Meanwhile, DETA-UiO-66 showed high adsorption capacities for citric acid and sorbic acid, indicating DETA-UiO-66's wide potentials in capturing various organic acid pollutants. [Display omitted] • The amino-functionalized material DETA-UiO-66 was first synthesized by grafting diethylenetriamine onto robust UiO-66 via post-synthetic modification. • DETA-functionalized materials were applied to the adsorptive removal of organic acid pollutants, showing excellent adsorption performance. • Superior performance was observed on the DETA-UiO-66 prepared with high thermal stability proved by the TGA curve and excellent chemical resistance after immersion in acidic and basic solutions. • Adsorption mechanism was proposed involving the dominant acid-base interaction and weak electrostatic interaction. [ABSTRACT FROM AUTHOR]