Your browser does not support JavaScript!

Αρχική    Συλλογές    Τύπος Εργασίας    Διδακτορικές διατριβές  

Διδακτορικές διατριβές

Τρέχουσα Εγγραφή: 20 από 2042

Πίσω στα Αποτελέσματα Προηγούμενη σελίδα
Επόμενη σελίδα
Προσθήκη στο καλάθι
[Προσθήκη στο καλάθι]
Κωδικός Πόρου 000428737
Τίτλος Design of bulky substituted porphyrin arrays for light harvesting applications
Άλλος τίτλος Σχεδιασμός πορφυρινικών συστημάτων με ογκώδειες υποκαταστάτες για εφαρμογές εκμετάλλευσης της ηλιακής ακτινοβολίας
Συγγραφέας Χαρισιάδης, Αστέριος Δ
Σύμβουλος διατριβής Κουτσολέλος, Αθανάσιος Γ.
Μέλος κριτικής επιτροπής Αγγαρίδης, Παναγιώτης
Δημάδης, Κωνσταντίνος
Κιτσόπουλος, Θεοφάνης
Μήλιος, Κωνσταντίνος
Ταγματάρχης, Νικόλαος
Τρικαλίτης, Παντελής
Περίληψη This Doctoral Thesis describes the development of novel porphyrin conjugates and their investigation as photosensitizers in numerous solar energy harvesting applications. Particularly, several appropriately designed porphyrin entities are presented herein that were either functionalized with appropriate bulky peripheral substituents or other units, such as fullerenes, cobalt-catalyst or boron dipyrromethene (BODIPY) compounds. These newly formed porphyrin-based entities were comprehensively examined as lightharnessers in artificial photosynthetic schemes, in dye-sensitized solar cells, in photoelectrochemical hydrogen evolving devices and in light-emitting electrochemical cells. In order to achieve the formation of the different reported hybrids, various synthetic approaches were applied. In the third chapter of this dissertation, steady-state and time-resolved photophysical investigations of the energy/electron transfer processes in artificial photosynthetic models are reported. Particularly, these systems are comprised of molecules that act as energy donors, fullerene-derivatives as electron acceptors and electron donating porphyrin entities. For the successful construction of these supramolecucar assemblies, two different types of non-covalent interactions were employed, namely electrostatic interactions and metal to ligand coordination. Various parameters that determine the efficacy of such arrays were thoroughly investigated, such as the association constant and the lifetime of the charge-separated state. The next section deals with the synthesis of various porphyrin-based derivatives and their application as photosensitizers in photovoltaic devices. Specifically, two modified porphyrin derivatives bearing different anchoring groups, a new porphyrin-fullerene dyad and four porphyrin-ruthenium polypyridyl complex dyads have been prepared and studied as sensitizers in n- and p-type dye-sensitized solar cells. Bulky substituents were inserted in the peripheries of all synthesized compounds, in order to eliminate the formation of aggregates onto the semiconductor surface that is one of the major limiting factors of such devices. Depending on the features that each derivative possesses, they were incorporated and studied in the corresponding configuration of solar cells. Furthermore, we connected a zinc-porphyrin to a cobalt catalytic unit, and the produced dyad was incorporated in a dye-sensitized photo-electrochemical solar cell toward hydrogen production. This system was fully characterized and fluorescence spectroscopic measurements, in particular, revealed that an electron transfer possibly occurs from the porphyrin sensitizer to the catalyst. This indication was confirmed by the catalytic experiments conducted, since hydrogen evolution was detected upon device operation. Last but not least, four triazole-linked porphyrin-BODIPY polyads were prepared, in which an increasing number of BODIPY chromophores were connected to the periphery of the central platinum-porphyrinic core. The photo-physical and electrochemical characterization of the novel polyads are presented in this part of the thesis. These hybrids will be used as red-emitters in light-emitting electrochemical cells and these measurements are still in progress.
Φυσική περιγραφή xxxi, 277 σ. : πίν., σχήμ., εικ. ; 30 εκ.
Γλώσσα Αγγλικά
Θέμα BODIPY
Cobalt catalyst
Dye-sensitized photo-electrochemical solar cell
Dye-sensitized solar cells
Energy/electron transfer
Fullerene
H2 evolution
Light-emitting electrochemical cells
Ηλεκτροχημικά κελιά εκπομπής φωτός
Ηλιακές κυψελίδες
Καταλύτης κοβαλτίου
Μεταφορά ενέργειας/ηλεκτρονίων
Παραγωγή H2
Πορφυρίνη
Φουλερένιο
Φωτο-ηλεκτροχημικά κελιά φωτοευαισθητοποιούμενης χρωστικής
Φωτοευαισθητοποιούμενης χρωστικής
Ημερομηνία έκδοσης 2020-01-10
Συλλογή   Σχολή/Τμήμα--Σχολή Θετικών και Τεχνολογικών Επιστημών--Τμήμα Χημείας--Διδακτορικές διατριβές
  Τύπος Εργασίας--Διδακτορικές διατριβές
Μόνιμη Σύνδεση https://elocus.lib.uoc.gr//dlib/7/c/b/metadata-dlib-1583228744-976094-19780.tkl Bookmark and Share
Εμφανίσεις 70

Ψηφιακά τεκμήρια
No preview available

Δεν έχετε δικαιώματα για να δείτε το έγγραφο.
Δεν θα είναι διαθέσιμο έως: 2022-01-10