Anodic Electrodeposition of Several Metal Organic Framework Thin Films on Indium Tin Oxide Glass

We present the rapid synthesis of a series of metal–organic framework (MOF) thin films on indium tin oxide (ITO) glass. ITO was first electrodeposited with either copper or zinc microcrystalline films (Cu-ITO and Zn-ITO, respectively) from simple aqueous/ethanol salt solutions. These metallic deposits served as the metal cation source during their partial anodic dissolution and the initial nucleation sites during electrochemical MOF (EMOF) film growth. Four different EMOF films were prepared by this method. HKUST-1 and the two-dimensional (2D) cationic framework [Cu(C10H8N2)2+]Br2(CBBr) were each grown on Cu-ITO. Zn6(OH)3(BTC)3(H20)3·7H2O (Zn-BTC, BTC = benzene tricarboxylate) and the 2D framework [Zn(BPDC)(H2O)]·H2O (Zn-BPDC, BPDC = 2,2′-bipyridine-5,5′-dicarboxylate) were each grown on Zn-ITO. Physical characterization was carried out using grazing incidence X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Our results show these films were well adhered, homogeneous, self-closing, and of relatively low surface roughness in each case. The ability to vary the dimensionality, metal node, linker, and charge of the EMOF on a conductive transparent substrate opens up a wide range of possible compositions, properties, and applications.