@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} } @misc{ThielZehbeRoeseretal.2013, author = {Thiel, Kerstin and Zehbe, Rolf and Roeser, Jer{\^o}m{\´e} and Strauch, Peter and Enthaler, Stephan and Thomas, Arne}, title = {A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-95118}, pages = {1848 -- 1856}, year = {2013}, abstract = {A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.}, language = {en} }