{"id":{"repo_id":"tu-berlin","oai_identifier":"oai:depositonce.tu-berlin.de:11303/26784"},"canonical_url":"https://search.dev.ndltd.org/etd/tu-berlin/oai:depositonce.tu-berlin.de:11303/26784","repository":{"repo_id":"tu-berlin","name":"Technische Universität Berlin","base_url":"https://api-depositonce.tu-berlin.de/server/oai/request"},"display":{"title":"Carbazole-based porous organic polymers for photocatalytic hydrogen evolution","abstract":"Photocatalytic water splitting is a direct pathway to store solar energy in chemicals. Within the last decade, porous organic polymers (POPs) proved to be promising candidates to be applied as photocatalyst. Due to the variety of building blocks, the optical properties can be tuned towards the employment of visible light, which is mandatory achieving industrial relevant efficiencies. Monomers bearing electron-rich carbazole groups can easily be oxidative coupled yielding in carbazole-based porous organic polymers (CPOPs). Various CPOPs with varying monomer cores, specific for its certain application, were oxidative polymerized by applying iron(III) chloride as oxidative agent or by electro polymerization. Yet limited research has been conducted on the exact chemical structure of the resulting polymer or on alternative synthetic approaches. The first part of this thesis focuses on the coupling mechanism of the carbazole coupling applying various oxidative agents. With iron(III) chloride or with a mild organic oxidant the formed polymer is coupled via carbazole dimer formation. If a strong organic oxidant like DDQ is applied, further polymerization on a single carbazole group is possible. Depending on the amount and reaction time a polymer with higher rigidity and improved CO2 gas uptake results. Avoiding any metal-based oxidative agent, the dimer coupled polymer with improved surface areas can be synthesized via the metal-free synthesis method. The electro polymerization of carbazoles yielding thin polymer films is another metal-free synthesis approach of CPOPs. In the second part of the thesis such polymer films were applied in photocatalytic water splitting for the first time, showing excellent reproducibility, recyclability as well as stability after initial deposition of a co-catalyst. While the film thickness did not significantly change the photocatalytic activity it is beneficial to place several thin films adjacent or stack them to improve the easily accessible outer surface area. Another option is to employ a microstructured polymer film with increased now accessible vertical surface area in the photocatalysis. The results of this work were published in a research article entitled Carbazole‐Based Thin Microporous Polymer Films for Photocatalytic Hydrogen Evolution in the journal Advanced Materials. In the last part of this thesis a novel CPOP was introduced bearing an electron deficient triaryl borane core coupled to three carbazole groups. The resulting monomer proved to be highly emissive with a highly polarized excited state. Due to polymerization the absorption shifted from the UV region to the visible light region, which is beneficial for the application in photocatalysis. In the photocatalytic hydrogen evolution reaction (HER) both the monomer and the polymer showed photocatalytic activity in the absence of any metal-based co-catalyst. Theoretical and mechanistical studies showed that upon light absorption formed generated radical species can be transferred from the boron core to coordinated protons forming hydrogen radicals which couple to form hydrogen.","abstract_html":"Photocatalytic water splitting is a direct pathway to store solar energy in chemicals. Within the last decade, porous organic polymers (POPs) proved to be promising candidates to be applied as photocatalyst. Due to the variety of building blocks, the optical properties can be tuned towards the employment of visible light, which is mandatory achieving industrial relevant efficiencies. Monomers bearing electron-rich carbazole groups can easily be oxidative coupled yielding in carbazole-based porous organic polymers (CPOPs). Various CPOPs with varying monomer cores, specific for its certain application, were oxidative polymerized by applying iron(III) chloride as oxidative agent or by electro polymerization. Yet limited research has been conducted on the exact chemical structure of the resulting polymer or on alternative synthetic approaches. The first part of this thesis focuses on the coupling mechanism of the carbazole coupling applying various oxidative agents. With iron(III) chloride or with a mild organic oxidant the formed polymer is coupled via carbazole dimer formation. If a strong organic oxidant like DDQ is applied, further polymerization on a single carbazole group is possible. Depending on the amount and reaction time a polymer with higher rigidity and improved CO2 gas uptake results. Avoiding any metal-based oxidative agent, the dimer coupled polymer with improved surface areas can be synthesized via the metal-free synthesis method. The electro polymerization of carbazoles yielding thin polymer films is another metal-free synthesis approach of CPOPs. In the second part of the thesis such polymer films were applied in photocatalytic water splitting for the first time, showing excellent reproducibility, recyclability as well as stability after initial deposition of a co-catalyst. While the film thickness did not significantly change the photocatalytic activity it is beneficial to place several thin films adjacent or stack them to improve the easily accessible outer surface area. Another option is to employ a microstructured polymer film with increased now accessible vertical surface area in the photocatalysis. The results of this work were published in a research article entitled Carbazole‐Based Thin Microporous Polymer Films for Photocatalytic Hydrogen Evolution in the journal Advanced Materials. In the last part of this thesis a novel CPOP was introduced bearing an electron deficient triaryl borane core coupled to three carbazole groups. The resulting monomer proved to be highly emissive with a highly polarized excited state. Due to polymerization the absorption shifted from the UV region to the visible light region, which is beneficial for the application in photocatalysis. In the photocatalytic hydrogen evolution reaction (HER) both the monomer and the polymer showed photocatalytic activity in the absence of any metal-based co-catalyst. Theoretical and mechanistical studies showed that upon light absorption formed generated radical species can be transferred from the boron core to coordinated protons forming hydrogen radicals which couple to form hydrogen.","abstract_has_math":false,"creators":["Dippold, Veit Wilfried"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Thomas, Arne"],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026","date_published":"2026","updated_at":"2026-07-27T21:28:57Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":["https://creativecommons.org/licenses/by-sa/4.0/"],"identifier_entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://doi.org/10.14279/depositonce-25614"],"render_values":[{"text":"https://doi.org/10.14279/depositonce-25614","href":"https://doi.org/10.14279/depositonce-25614","code":true}]}]},"links":{"outbound_url":"https://depositonce.tu-berlin.de/handle/11303/26784","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Thomas, Arne"]},{"key":"dc:creator","label":"Author","values":["Dippold, Veit Wilfried"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-04-10T13:17:23Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-04-10T13:17:23Z"]},{"key":"dc:date.issued","label":"Date","values":["2026"]},{"key":"dc:type","label":"Dc Type","values":["Doctoral Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights.uri","label":"Rights URI","values":["https://creativecommons.org/licenses/by-sa/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://depositonce.tu-berlin.de/handle/11303/26784","https://doi.org/10.14279/depositonce-25614"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Photocatalytic water splitting is a direct pathway to store solar energy in chemicals. Within the last decade, porous organic polymers (POPs) proved to be promising candidates to be applied as photocatalyst. Due to the variety of building blocks, the optical properties can be tuned towards the employment of visible light, which is mandatory achieving industrial relevant efficiencies. Monomers bearing electron-rich carbazole groups can easily be oxidative coupled yielding in carbazole-based porous organic polymers (CPOPs). Various CPOPs with varying monomer cores, specific for its certain application, were oxidative polymerized by applying iron(III) chloride as oxidative agent or by electro polymerization. Yet limited research has been conducted on the exact chemical structure of the resulting polymer or on alternative synthetic approaches. The first part of this thesis focuses on the coupling mechanism of the carbazole coupling applying various oxidative agents. With iron(III) chloride or with a mild organic oxidant the formed polymer is coupled via carbazole dimer formation. If a strong organic oxidant like DDQ is applied, further polymerization on a single carbazole group is possible. Depending on the amount and reaction time a polymer with higher rigidity and improved CO2 gas uptake results. Avoiding any metal-based oxidative agent, the dimer coupled polymer with improved surface areas can be synthesized via the metal-free synthesis method. The electro polymerization of carbazoles yielding thin polymer films is another metal-free synthesis approach of CPOPs. In the second part of the thesis such polymer films were applied in photocatalytic water splitting for the first time, showing excellent reproducibility, recyclability as well as stability after initial deposition of a co-catalyst. While the film thickness did not significantly change the photocatalytic activity it is beneficial to place several thin films adjacent or stack them to improve the easily accessible outer surface area. Another option is to employ a microstructured polymer film with increased now accessible vertical surface area in the photocatalysis. The results of this work were published in a research article entitled Carbazole‐Based Thin Microporous Polymer Films for Photocatalytic Hydrogen Evolution in the journal Advanced Materials. In the last part of this thesis a novel CPOP was introduced bearing an electron deficient triaryl borane core coupled to three carbazole groups. The resulting monomer proved to be highly emissive with a highly polarized excited state. Due to polymerization the absorption shifted from the UV region to the visible light region, which is beneficial for the application in photocatalysis. In the photocatalytic hydrogen evolution reaction (HER) both the monomer and the polymer showed photocatalytic activity in the absence of any metal-based co-catalyst. Theoretical and mechanistical studies showed that upon light absorption formed generated radical species can be transferred from the boron core to coordinated protons forming hydrogen radicals which couple to form hydrogen.","Die photokatalytische Wasserspaltung ist ein direkter Weg um solare in chemische Energie umzuwandeln. Im Laufe des letzten Jahrzehnts bewiesen sich porös organische Polymere (POPs) als vielversprechende Photokatalysatoren. Durch eine Vielzahl an möglichen Monomeren können die optischen Eigenschaften hin zur Absorption des sichtbaren Lichts angepasst werden, was für das Erreichen industriell relevanter Wirkungsgrade nötig ist. Monomere mit elektronenreichen Carbazolgruppen können leicht oxidativ polymerisiert werden, um Carbazol basierte porös organische Polymere (CPOPs) herzustellen. Verschiedene CPOPs mit unterschiedlichen Monomerkernen, speziell für die jeweilige Anwendung, wurden bisher entweder mit Eisen(III)-chlorid als Oxidationsmittel oder mittels Elektropolymerisation hergestellt. Dennoch wurde bisher nur begrenzt untersucht, welche genaue chemische Struktur die Polymere besitzen oder welche alternative Syntheserouten möglich sind. Der erste Teil dieser Dissertation befasst sich mit dem Mechanismus der Kupplung von Carbazolen unter der Verwendung verschiedener Oxidationsmittel. Mit Eisen(III)-chlorid oder milden organischen Oxidationsmitteln erfolgt die Polymerisation über die Entstehung von Carbazoldimeren. Wenn ein starkes Oxidationsmittel wie DDQ eingesetzt wird, kann das entstandene Carbazoldimer weiter polymerisieren. Abhängig von der Menge an Oxidationsmittel und der Reaktionszeit resultiert ein Polymer mit höherer Steifigkeit und verbesserter CO2 Aufnahme. Trotz des Verzichts auf metallbasierte Oxidationsmittel lässt sich ebenfalls über die metallfreie Synthesemethode ein Dimer-gekoppeltes Polymer mit größerer Oberfläche herstellen. Die Elektropolymerisation von Carbazolen ist eine andere metallfreie Synthesemethode von CPOPs, um dünne Polymerfilme herzustellen. Im zweiten Teil der Arbeit wurden solche Polymerfilme erstmalig in der photokatalytischen Wasserspaltung eingesetzt und zeigten dabei hervorragende Reproduzierbarkeit, Wiederverwendbarkeit und Stabilität nach der Abscheidung eines Co-Katalysators. Da die Variation der Filmdicke die Aktivität nicht beeinflusst, ist es vorteilhaft, mehrere dünne Filme nebeneinander oder gestapelt anzuordnen, um die leicht zugängliche äußere Oberfläche zu vergrößern. Eine weitere Möglichkeit besteht darin, mikrostrukturierte Polymerfilme mit vergrößerter vertikaler, einfach zugänglicher Oberfläche in der Photokatalyse einzusetzen. Die Ergebnisse dieses Kapitels wurden in dem Forschungsartikel Carbazole‐Based Thin Microporous Polymer Films for Photocatalytic Hydrogen Evolution in der Zeitschrift Advanced Materials veröffentlicht. Im letzten Teil dieser Arbeit wurde ein neuartiges CPOP eingeführt, das einen elektronenarmen Triarylboran Kern mit drei Carbazolgruppen als Monomer enthält. Das lumineszente Monomer zeigte einen stark polarisierten angeregten Zustand. Durch die Polymerisation verschob sich die Absorption vom UV-Bereich in den sichtbaren Bereich, was für den Einsatz in der Photokatalyse vorteilhaft ist. In der photokatalytischen Wasserstoffentwicklung (HER) zeigten sowohl das Monomer als auch das Polymer ohne den Einsatz eines metallbasierten Co-Katalysators Aktivität. Theoretische und mechanistische Studien zeigten, dass durch Lichtabsorption Radikale erzeugt werden, welche vom Borzentrum auf ein koordiniertes Proton übertragen werden können, wobei Wasserstoffradikale entstehen, die anschließend miteinander zu einem Wasserstoffmolekül kombinieren."]},{"key":"dc:title","label":"Title","values":["Carbazole-based porous organic polymers for photocatalytic hydrogen evolution"]}]}],"canonical_facts":{"dc:contributor.advisor":["Thomas, Arne"],"dc:creator":["Dippold, Veit Wilfried"],"dc:date.accessioned":["2026-04-10T13:17:23Z"],"dc:date.available":["2026-04-10T13:17:23Z"],"dc:date.issued":["2026"],"dc:description.abstract":["Photocatalytic water splitting is a direct pathway to store solar energy in chemicals. Within the last decade, porous organic polymers (POPs) proved to be promising candidates to be applied as photocatalyst. Due to the variety of building blocks, the optical properties can be tuned towards the employment of visible light, which is mandatory achieving industrial relevant efficiencies. Monomers bearing electron-rich carbazole groups can easily be oxidative coupled yielding in carbazole-based porous organic polymers (CPOPs). Various CPOPs with varying monomer cores, specific for its certain application, were oxidative polymerized by applying iron(III) chloride as oxidative agent or by electro polymerization. Yet limited research has been conducted on the exact chemical structure of the resulting polymer or on alternative synthetic approaches. The first part of this thesis focuses on the coupling mechanism of the carbazole coupling applying various oxidative agents. With iron(III) chloride or with a mild organic oxidant the formed polymer is coupled via carbazole dimer formation. If a strong organic oxidant like DDQ is applied, further polymerization on a single carbazole group is possible. Depending on the amount and reaction time a polymer with higher rigidity and improved CO2 gas uptake results. Avoiding any metal-based oxidative agent, the dimer coupled polymer with improved surface areas can be synthesized via the metal-free synthesis method. The electro polymerization of carbazoles yielding thin polymer films is another metal-free synthesis approach of CPOPs. In the second part of the thesis such polymer films were applied in photocatalytic water splitting for the first time, showing excellent reproducibility, recyclability as well as stability after initial deposition of a co-catalyst. While the film thickness did not significantly change the photocatalytic activity it is beneficial to place several thin films adjacent or stack them to improve the easily accessible outer surface area. Another option is to employ a microstructured polymer film with increased now accessible vertical surface area in the photocatalysis. The results of this work were published in a research article entitled Carbazole‐Based Thin Microporous Polymer Films for Photocatalytic Hydrogen Evolution in the journal Advanced Materials. In the last part of this thesis a novel CPOP was introduced bearing an electron deficient triaryl borane core coupled to three carbazole groups. The resulting monomer proved to be highly emissive with a highly polarized excited state. Due to polymerization the absorption shifted from the UV region to the visible light region, which is beneficial for the application in photocatalysis. In the photocatalytic hydrogen evolution reaction (HER) both the monomer and the polymer showed photocatalytic activity in the absence of any metal-based co-catalyst. Theoretical and mechanistical studies showed that upon light absorption formed generated radical species can be transferred from the boron core to coordinated protons forming hydrogen radicals which couple to form hydrogen.","Die photokatalytische Wasserspaltung ist ein direkter Weg um solare in chemische Energie umzuwandeln. Im Laufe des letzten Jahrzehnts bewiesen sich porös organische Polymere (POPs) als vielversprechende Photokatalysatoren. Durch eine Vielzahl an möglichen Monomeren können die optischen Eigenschaften hin zur Absorption des sichtbaren Lichts angepasst werden, was für das Erreichen industriell relevanter Wirkungsgrade nötig ist. Monomere mit elektronenreichen Carbazolgruppen können leicht oxidativ polymerisiert werden, um Carbazol basierte porös organische Polymere (CPOPs) herzustellen. Verschiedene CPOPs mit unterschiedlichen Monomerkernen, speziell für die jeweilige Anwendung, wurden bisher entweder mit Eisen(III)-chlorid als Oxidationsmittel oder mittels Elektropolymerisation hergestellt. Dennoch wurde bisher nur begrenzt untersucht, welche genaue chemische Struktur die Polymere besitzen oder welche alternative Syntheserouten möglich sind. Der erste Teil dieser Dissertation befasst sich mit dem Mechanismus der Kupplung von Carbazolen unter der Verwendung verschiedener Oxidationsmittel. Mit Eisen(III)-chlorid oder milden organischen Oxidationsmitteln erfolgt die Polymerisation über die Entstehung von Carbazoldimeren. Wenn ein starkes Oxidationsmittel wie DDQ eingesetzt wird, kann das entstandene Carbazoldimer weiter polymerisieren. Abhängig von der Menge an Oxidationsmittel und der Reaktionszeit resultiert ein Polymer mit höherer Steifigkeit und verbesserter CO2 Aufnahme. Trotz des Verzichts auf metallbasierte Oxidationsmittel lässt sich ebenfalls über die metallfreie Synthesemethode ein Dimer-gekoppeltes Polymer mit größerer Oberfläche herstellen. Die Elektropolymerisation von Carbazolen ist eine andere metallfreie Synthesemethode von CPOPs, um dünne Polymerfilme herzustellen. Im zweiten Teil der Arbeit wurden solche Polymerfilme erstmalig in der photokatalytischen Wasserspaltung eingesetzt und zeigten dabei hervorragende Reproduzierbarkeit, Wiederverwendbarkeit und Stabilität nach der Abscheidung eines Co-Katalysators. Da die Variation der Filmdicke die Aktivität nicht beeinflusst, ist es vorteilhaft, mehrere dünne Filme nebeneinander oder gestapelt anzuordnen, um die leicht zugängliche äußere Oberfläche zu vergrößern. Eine weitere Möglichkeit besteht darin, mikrostrukturierte Polymerfilme mit vergrößerter vertikaler, einfach zugänglicher Oberfläche in der Photokatalyse einzusetzen. Die Ergebnisse dieses Kapitels wurden in dem Forschungsartikel Carbazole‐Based Thin Microporous Polymer Films for Photocatalytic Hydrogen Evolution in der Zeitschrift Advanced Materials veröffentlicht. Im letzten Teil dieser Arbeit wurde ein neuartiges CPOP eingeführt, das einen elektronenarmen Triarylboran Kern mit drei Carbazolgruppen als Monomer enthält. Das lumineszente Monomer zeigte einen stark polarisierten angeregten Zustand. Durch die Polymerisation verschob sich die Absorption vom UV-Bereich in den sichtbaren Bereich, was für den Einsatz in der Photokatalyse vorteilhaft ist. In der photokatalytischen Wasserstoffentwicklung (HER) zeigten sowohl das Monomer als auch das Polymer ohne den Einsatz eines metallbasierten Co-Katalysators Aktivität. Theoretische und mechanistische Studien zeigten, dass durch Lichtabsorption Radikale erzeugt werden, welche vom Borzentrum auf ein koordiniertes Proton übertragen werden können, wobei Wasserstoffradikale entstehen, die anschließend miteinander zu einem Wasserstoffmolekül kombinieren."],"dc:identifier.uri":["https://depositonce.tu-berlin.de/handle/11303/26784","https://doi.org/10.14279/depositonce-25614"],"dc:language.iso":["en"],"dc:rights.uri":["https://creativecommons.org/licenses/by-sa/4.0/"],"dc:title":["Carbazole-based porous organic polymers for photocatalytic hydrogen evolution"],"dc:type":["Doctoral Thesis"]},"updated_at":"2026-07-27T21:28:57Z"}