Enhancing water stability of MIL-101(Cr) by doping Ni(II).

• Ni(II) ions were introduced into MIL-101(Cr) structure by pre-synthesis. • Enhanced water stability without introducing hydrophobic groups or other modifiers. • Ni/MIL-101(Cr) maintained the original morphology and characteristic. • The stability of Ni/MIL-101(Cr) in different pH aqueous solutions was reported. Ni(II) ions doped MIL-101(Cr) metal organic framework materials were synthesized for the first time by pre-synthesis doping to improve their water stability. The samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), energy-dispersive spectroscopy instrument (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N 2 adsorption-desorption measurements, which persuasively demonstrated the effective combination of Ni(II) ions with the framework. The results showed that compared with undoped MIL-101(Cr), Ni-doped MIL-101(Cr) retained the original large specific surface area and pore size characteristics, and significantly improves the water stability of the skeleton. The water stability of Ni-doped MIL-101(Cr) in water environment with different pH has been significantly improved, which has important guiding significance for the application of MOFs in practical engineering. [ABSTRACT FROM AUTHOR]