Manufacture of dense coatings of Cu3(BTC)2 (HKUST-1) on α-alumina

By a seeding approach coatings of copper benzene tricarboxylate (Cu3(BTC)2, also known as HKUST-1) are obtained on α-alumina. The obtained crystal densities, order and intergrowth improve the best results reported up to now in the literature for any metal-organic framework material. The effect of synthesis conditions on the morphology and crystal size of Cu3(BTC)2 was determined to optimize the strategies for the synthesis of continuous layers. Seeding with coordination polymers of different morphology resulted in control of crystal growth of the coating. Two seeding suspensions yielded the best intergrowth of crystals. Spin-coating the support with a one-dimensional Cu(II)–BTC coordination polymer suspension resulted in a high density coating with randomly oriented crystals of ∼2 μm, while using amorphous MOF precursors (proto-MOFs) as seeds, coatings with crystals of ∼5 μm were obtained.