Direct growth of Keggin polyoxometalates incorporated copper 1,3,5-benzenetricarboxylate metal organic framework films on a copper metal substrate

Abstract Keggin heteropolyacid incorporated Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylic acid) thin films were grown on metallic Cu substrates in various solvents at ambient conditions. The Keggin heteropolyacid templated the growth of Cu3(BTC)2 crystals while the Cu substrate served as Cu2+-ion source. To obtain smooth, homogeneous films the optimal growth conditions found were in an ethanolic solution in contact with ambient air. X-ray diffraction measurements showed a preferred (100) orientation of the Cu3(BTC)2 crystals in ethanol while the use of a water-based solvent yielded a dominating (111) orientation.