@article{LaquaiSchauppGriescheetal.2022, author = {Laquai, Ren{\´e} and Schaupp, Thomas and Griesche, Axel and M{\"u}ller, Bernd R. and Kupsch, Andreas and Hannemann, Andreas and Kannengiesser, Thomas and Bruno, Giovanni}, title = {Quantitative analysis of hydrogen-assisted microcracking in duplex stainless steel through X-ray refraction 3D imaging}, series = {Advanced engineering materials}, volume = {24}, journal = {Advanced engineering materials}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1527-2648}, doi = {10.1002/adem.202101287}, pages = {10}, year = {2022}, abstract = {While the problem of the identification of mechanisms of hydrogen-assisted damage has and is being thoroughly studied, the quantitative analysis of such damage still lacks suitable tools. In fact, while, for instance, electron microscopy yields excellent characterization, the quantitative analysis of damage requires at the same time large field-of-views and high spatial resolution. Synchrotron X-ray refraction techniques do possess both features. Herein, it is shown how synchrotron X-ray refraction computed tomography (SXRCT) can quantify damage induced by hydrogen embrittlement in a lean duplex steel, yielding results that overperform even those achievable by synchrotron X-ray absorption computed tomography. As already reported in the literature, but this time using a nondestructive technique, it is shown that the hydrogen charge does not penetrate to the center of tensile specimens. By the comparison between virgin and hydrogen-charged specimens, it is deduced that cracks in the specimen bulk are due to the rolling process rather than hydrogen-assisted. It is shown that (micro)cracks propagate from the surface of tensile specimens to the interior with increasing applied strain, and it is deduced that a significant crack propagation can only be observed short before rupture.}, language = {en} } @article{HeroldAignerGrilletal.2019, author = {Herold, Heike M. and Aigner, Tamara Bernadette and Grill, Carolin E. and Kr{\"u}ger, Stefanie and Taubert, Andreas and Scheibel, Thomas R.}, title = {SpiderMAEn}, series = {Bioinspired, Biomimetic and Nanobiomaterials}, volume = {8}, journal = {Bioinspired, Biomimetic and Nanobiomaterials}, number = {1}, publisher = {ICE Publishing}, address = {Westminister}, issn = {2045-9858}, doi = {10.1680/jbibn.18.00007}, pages = {99 -- 108}, year = {2019}, abstract = {A growing energy demand requires new and preferably renewable energy sources. The infinite availability of solar radiation makes its conversion into storable and transportable energy forms attractive for research as well as for the industry. One promising example of a transportable fuel is hydrogen (H-2), making research into eco-friendly hydrogen production meaningful. Here, a hybrid system was developed using newly designed recombinant spider silk protein variants as a template for mineralization with inorganic titanium dioxide and gold. These bioinspired organic/inorganic hybrid materials allow for hydrogen production upon light irradiation. To begin with, recombinant spider silk proteins bearing titanium dioxide and gold-binding moieties were created and processed into structured films. These films were modified with gold and titanium dioxide in order to produce a photocatalyst. Subsequent testing revealed hydrogen production as a result of light-induced hydrolysis of water. Therefore, the novel setup presented here provides access to a new principle of generating advanced hybrid materials for sustainable hydrogen production and depicts a promising platform for further studies on photocatalytic production of hydrogen, the most promising future fuel.}, language = {en} } @misc{KuehnLiNakatenetal.2017, author = {K{\"u}hn, Michael and Li, Qi and Nakaten, Natalie Christine and Kempka, Thomas}, title = {Integrated subsurface gas storage of CO2 and CH4 offers capacity and state-of-the-art technology for energy storage in China}, series = {Energy procedia}, volume = {125}, journal = {Energy procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {10.1016/j.egypro.2017.08.039}, pages = {14 -- 18}, year = {2017}, abstract = {Integration and development of the energy supply in China and worldwide is a challenge for the years to come. The innovative idea presented here is based on an extension of the "power-to-gas-to-power" technology by establishing a closed carbon cycle. It is an implementation of a low-carbon energy system based on carbon dioxide capture and storage (CCS) to store and reuse wind and solar energy. The Chenjiacun storage project in China compares well with the German case study for the towns Potsdam and Brandenburg/Havel in the Federal State of Brandenburg based on the Ketzin pilot site for CCS.}, language = {en} } @phdthesis{Fettkenhauer2015, author = {Fettkenhauer, Christian}, title = {Ionothermale Synthese funktioneller Kohlenstoffnitrid basierter Materialien}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-78087}, school = {Universit{\"a}t Potsdam}, pages = {xii, 123}, year = {2015}, abstract = {Die Doktorarbeit behandelt die Synthese Kohlenstoffnitrid basierter Materialien in eutektischen Mischungen bivalenter Metallchloride. Der Fokus liegt dabei auf ZnCl2-, SnCl2- und CoCl2-haltigen eutektischen Mischungen, in denen die Kondensation gebr{\"a}uchlicher organischer Precursoren durchgef{\"u}hrt wird. Im Rahmen dessen wird untersucht wie durch die Reaktionsf{\"u}hrung in Salzschmelzen unterschiedlicher Lewis-Acidit{\"a}t, neben der Molek{\"u}lstruktur andere charakteristische Eigenschaften, wie Morphologie, Kristallinit{\"a}t und spezifische Oberfl{\"a}chen, der Materialien kontrolliert werden k{\"o}nnen. Dar{\"u}ber hinaus werden die optischen Eigenschaften der Materialien er{\"o}rtert und in diesem Zusammenhang die Eignung als Photokatalysatoren f{\"u}r den oxidativen Abbau organischer Farbstoffe und f{\"u}r die photokatalytische Wasserreduktion bzw. -oxidation untersucht. Zus{\"a}tzlich wird gezeigt, wie im System LiCl/KCl in einem einstufigen Prozess edelmetallfreie Kohlenstoffnitrid Komposite zur photokatalytischen Wasserreduktion hergestellt werden k{\"o}nnen.}, language = {de} } @misc{WirthNeumannAntoniettietal.2014, author = {Wirth, Jonas and Neumann, Rainer and Antonietti, Markus and Saalfrank, Peter}, title = {Adsorption and photocatalytic splitting of water on graphitic carbon nitride}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74391}, pages = {15917 -- 15926}, year = {2014}, abstract = {Graphitic carbon nitride, g-C₃N₄, is a promising organic photo-catalyst for a variety of redox reactions. In order to improve its efficiency in a systematic manner, however, a fundamental understanding of the microscopic interaction between catalyst, reactants and products is crucial. Here we present a systematic study of water adsorption on g-C₃N₄ by means of density functional theory and the density functional based tight-binding method as a prerequisite for understanding photocatalytic water splitting. We then analyze this prototypical redox reaction on the basis of a thermodynamic model providing an estimate of the overpotential for both water oxidation and H⁺ reduction. While the latter is found to occur readily upon irradiation with visible light, we derive a prohibitive overpotential of 1.56 eV for the water oxidation half reaction, comparing well with the experimental finding that in contrast to H₂ production O₂ evolution is only possible in the presence of oxidation cocatalysts.}, language = {en} } @article{WirthNeumannAntoniettietal.2014, author = {Wirth, Jonas and Neumann, Rainer and Antonietti, Markus and Saalfrank, Peter}, title = {Adsorption and photocatalytic splitting of water on graphitic carbon nitride}, series = {physical chemistry, chemical physics : PCCP}, volume = {2014}, journal = {physical chemistry, chemical physics : PCCP}, number = {16}, issn = {1463-9076}, doi = {10.1039/c4cp02021a}, pages = {15917 -- 15926}, year = {2014}, abstract = {Graphitic carbon nitride, g-C₃N₄, is a promising organic photo-catalyst for a variety of redox reactions. In order to improve its efficiency in a systematic manner, however, a fundamental understanding of the microscopic interaction between catalyst, reactants and products is crucial. Here we present a systematic study of water adsorption on g-C₃N₄ by means of density functional theory and the density functional based tight-binding method as a prerequisite for understanding photocatalytic water splitting. We then analyze this prototypical redox reaction on the basis of a thermodynamic model providing an estimate of the overpotential for both water oxidation and H⁺ reduction. While the latter is found to occur readily upon irradiation with visible light, we derive a prohibitive overpotential of 1.56 eV for the water oxidation half reaction, comparing well with the experimental finding that in contrast to H₂ production O₂ evolution is only possible in the presence of oxidation cocatalysts.}, language = {en} }