| dc.description.abstract | This thesis describes synthesis, analysis, photo- and electro-catalytic experiments of cobalt(II) based
metal organic framework (MOF) thin films. Organic molecules 4,4’-bipyridine (44BP), 2,4-dihydroxy
terephthalic acid (DHTA) and amino terephthalic acid (ATA) were used as linkers. MOFs thin films
were prepared on an acid or amine functionalized gold substrate or FTO glass. Homogeneous films of
Co44BP were prepared using a layer-by-layer synthesis approach. The coordination of 44BP to the
cobalt was observed with IR and Raman measurements. Identical crystalline thin films of Co44BP
anchored on acid, hydroxide and pyridine terminated surfaces were revealed by XRD measurements.
Homogeneous distributed Co44BP crystals over the surfaces were confirmed with Time of Flight Secondary Ion Mass Spectrometry (ToFSIMS) measurements. Thin films of CoDHTA and CoATA were
prepared by spin coating. Vibrational analysis with IR and Raman, and DFT calculations showed
that not only the acid groups, but the substituents, -OH and -NH2, were also involved in the coordination. Combined with XRD analysis, the synthesis of the thin films resulted in poly crystalline
CoDHTA and amorphous CoATA coatings. XRD measurements and Photo induced Force Microscopy
(PiFM) on the CoDHTA thin films indicated that the crystalline orientation of CoDHTA di↵ered on
acid terminated surfaces compared to hydroxide terminated surfaces. For CoATA thin films, these
measurements revealed very homogeneous amorphous films in both spatial and chemical perspectives.
Ligand to metal charge transfer (LMCT) energies of CoDHTA and CoATA were observed at 382 nm
and 375 nm respectively. Transients were observed with transient absorption spectroscopy (TAS) in
CoDHTA and Co44BP with half-lifes up to respectively 139 and 141 ns. Activity in the catalytic
testing of CoDHTA@FTO on the photoreduction of CO2 and electrochemical reduction of methylene
blue were barely observed. During the electrocatalysis, the coating was destroyed. | |
