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The formation of a water-sensitive metal–organic framework (MOF), Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylate), in a water/ethanol solvent system was studied systematically. The X-ray diffraction results prove that the MOF cannot form in pure water or in a water/ethanol mixture with a small amount of ethanol. As the ethanol content exceeds 30 vol%, a crystalline MOF can be obtained. The scanning electron microscope images of the as-synthesized MOFs show the formation of MOF nanoparticles with an average size of 20–300 nm. The MOF particle size decreased with increasing ethanol content in the mixed solvent. The FT-IR spectra further support that the MOF formation occurs in water/ethanol mixtures with ethanol volume ratios higher than 30 vol%. Thermogravimetric analysis showed that the MOF is stable up to 300 °C. Moreover, the FT-IR spectra and thermogravimetric analysis gave consistent information on the solvent amount entrapped in the MOF pores. The porosity of the MOFs was determined using a N2 adsorption–desorption method. When the ethanol volume ratio reached 75%, the largest SBET value of 1067 m2 g−1 and Vt value of 0.52 cm3 g−1 were obtained. The possible mechanism for MOF formation in water/ethanol solvent systems and the dependence of the MOF size on the solvent composition was discussed from the view of hydrogen bond strength between solvent molecules and the ligands in different water/ethanol solvent systems.

Herein it was found that gas can be utilized as an activator to promote metal-organic framework (MOF) crystallization in IL at room temperature. The ultra-small MOF nanoparticles were obtained, and their size and porosity properties can be easily modulated by controlling gas pressure. The as-synthesized nano-sized Cu-MOF is an excellent candidate catalyst for the solvent-free oxidation of cyclohexene with oxygen.

CuO nanoleaves with a mesoporous structure were formed in an aqueous solution of triethylamine at room temperature. The growth process of the CuO nanoleaves in a triethylamine solution was investigated by varying the reaction time. It is shown that the CuO nanostructures form by reconstructive transformation from Cu(OH)2, going through a 0D nanoparticle → 1D nanowire → 2D nanoleaf dimensional transition process. The mechanism for the amine-induced formation of CuO at room temperature was studied by using different aliphatic amines. It is revealed that the amines play multiple roles on CuO formation, i.e. acting as an alkali, dominating the Cu(OH)2 to CuO transformation, and directing the oriented crystal growth of CuO. This route is simple, rapid, involves no additional alkalis or directing agents, and can proceed at room temperature. The as synthesized CuO exhibits excellent catalytic activity for cyclohexene oxidation with oxygen under solvent-free conditions.