Preparation of palygorskite/MIL-88A(Fe) composites for high-efficient removal of Congo red

Metal-organic frameworks with favorable adsorption performance have attracted increasing interesting in water treatment. However, the poor pH stability and tedious preparation processes are still the major disadvantages for practical application. To address these problems, novel palygorskite/MIL-88A(Fe) (PMFe-x) composites were prepared via a convenient in-situ growth strategy after incorporation of natural palygorskite into MIL-88A(Fe). The characterization results revealed that Pal was incorporated into the MIL-88A(Fe) crystal structure, and thus the as-prepared PMFe-x composites presented excellent adsorption performance and acid/alkali stability in the pH range of 2–12. The maximum adsorption capacity of composites to Congo red reached 1141.4 mg g−1 within 3 h, which was much higher than that of pure MIL-88A(Fe). Moreover, the spent MOFs composites after adsorption of dye were facilely regenerated by calcination treatment at 300 °C under N2 atmosphere, and the adsorption capacity of the regenerated composites to Congo red maintained more than 360 mg g-1 after five cycles, Due to the excellent acid/alkali resistance and adsorption properties, the obtained MOFs composites presented good application prospects in water treatment.