Cu2O Mediated Synthesis of Metal–Organic Framework UiO-66 in Nanometer Scale

Controlled synthesis of metal–organic frameworks (MOFs) in nanometer scale is highly desired for the optimization of properties and the extending of applications. In this work, Cu2O was used as additive for the first time in the synthesis of zirconium-based MOF UiO-66. We found that the amount of Cu2O additive had an important impact on downsizing the crystal size of UiO-66. Cu2O additive plays a role of rate controller of crystal growth of UiO-66 crystals by their competitive coordination behavior with the linker H2BDC between the [Zr–O] clusters. This generates a depleted H2BDC concentration for the coordination with the [Zr–O] clusters for constructing the UiO-66 framework, which favors the production of small crystals. As a result, well-dispersed nanometer scale UiO-66 crystals with mean crystal size of 40 nm can be easily synthesized by the addition of Cu2O. The as-synthesized nanometer scale UiO-66 crystals have a pure crystal structure with high crystallinity and superior porosity.