The controlled regulation of morphology and size of HKUST-1 by “coordination modulation method”

Three types of modulators, including sodium formate, sodium acetate and triethylamine were used to tailor the morphology and size of HKUST-1 crystals by “coordination modulation method”. Through exploring the reaction parameters during the synthesis of HKUST-1, fascinating crystals morphologies, including hierarchical octahedral-shape crystals and nanocrystals were obtained by a solvothermal treatment. This paper discloses two essential functions of the modulator for the fabrication of uniform nanocrystals: Adjusting the proper acid–base environment of the reaction medium which governs the nucleation process and capping groups capable of inhibiting crystallites from growing. Moreover, samples were fully characterized by various techniques and the formation mechanism of the hierarchical octahedral-shape crystals was deduced.

Fascinating crystals morphologies, including hierarchical octahedral-shape crystals and nanocrystals were obtained by employing various modulators, including sodium formate, sodium acetate and triethylamine. This graphical discloses two essential parameters for miniaturizing the size of HKUST-1 crystals to the nanometer scale. One is the proper acid–base environment of the reaction medium which governs deprotonation of the organic linker and, hence, the nucleation process. The other is the use of capping groups capable of inhibiting crystallites from growing. These findings have important significance for extending this method to the synthesis of other types of NMOF crystals and may help to perform size- and shape-controlled syntheses of nano- and microscale HKUST-1 bulk materials and supported HKUST-1 membranes/films in a more rational way.Figure optionsDownload as PowerPoint slideHighlights
► Two functions of modulator to prepare nanosized MOFs crystal have been disclosed.
► Modulator adjusts the pH, and owns the capping groups.
► Sodium formate as a modulator, spherical monodisperse nanocystals can be prepared.
► Microcrystal has been obtained with addition of sodium acetate as modulator.
► Hierarchical octahedral-shape crystal was synthesized using the TEA as modulator.