Environmentally benign dry-gel conversions of Zr-based UiO metal-organic frameworks with high yield and the possibility of solvent re-use

Herein we report an alternative synthesis method for Zr-based UiO metal-organic frameworks (MOFs), namely dry-gel conversion (DGC). It was possible to synthesize nano-to microsized UiO-66, UiO-66-NH2 and UiO-67 with high crystallinity, high surface area and increased yield using only one-sixth or less of the solvent volume compared to the solution synthesis on the same scale. Additionally, it is shown that solvent re-use is possible over at least five synthesis runs making the DGC method an ecological and extremely solvent-economical route to obtain Zr-based UiO-MOFs with reproducible results.