Enhanced Hydrostability in Ni-Doped MOF‑5

Ni-doped MOF-5s were successfully synthesized for the first time via solvothermal crystallization process to enhance the hydrostability. Several characterization techniques, including X-ray diffraction (XRD), thermogravimetrical analysis (TGA), scanning electron microscopy (SEM), energy-dispersive spectroscopy instrument (EDS), inductively coupled plasma (ICP), infrared spectroscopy (IR), atomic sorption, diffuse-reflectance UV–vis spectroscopy, and gas sorption measurement, strongly support the effective incorporation of Ni(II) ions into the framework. The results demonstrated that the Ni-doped MOF-5s not only exhibit larger Langmuir specific surface areas and larger pores than the undoped MOF-5, but also significantly enhance water resistance of the framework. The H2 uptake capacity of undoped MOF-5 drops rapidly when exposed to the ambient air, whereas the H2 adsorptions of the Ni-doped MOF-5s remain stable for 4 days.