@article{XuShalomPiersimonietal.2015, author = {Xu, Jingsan and Shalom, Menny and Piersimoni, Fortunato and Antonietti, Markus and Neher, Dieter and Brenner, Thomas J. K.}, title = {Color-Tunable Photoluminescence and NIR Electroluminescence in Carbon Nitride Thin Films and Light-Emitting Diodes}, series = {Advanced optical materials}, volume = {3}, journal = {Advanced optical materials}, number = {7}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2195-1071}, doi = {10.1002/adom.201500019}, pages = {913 -- 917}, year = {2015}, language = {en} } @article{XuCaoBrenneretal.2015, author = {Xu, Jingsan and Cao, Shaowen and Brenner, Thomas J. K. and Yang, Xiaofei and Yu, Jiaguo and Antonietti, Markus and Shalom, Menny}, title = {Supramolecular Chemistry in Molten Sulfur: Preorganization Effects Leading to Marked Enhancement of Carbon Nitride Photoelectrochemistry}, series = {Advanced functional materials}, volume = {25}, journal = {Advanced functional materials}, number = {39}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1616-301X}, doi = {10.1002/adfm.201502843}, pages = {6265 -- 6271}, year = {2015}, abstract = {Here, a new method for enhancing the photoelectrochemical properties of carbon nitride thin films by in situ supramolecular-driven preorganization of phenyl-contained monomers in molten sulfur is reported. A detailed analysis of the chemical and photophysical properties suggests that the molten sulfur can texture the growth and induce more effective integration of phenyl groups into the carbon nitride electrodes, resulting in extended light absorption alongside with improved conductivity and better charge transfer. Furthermore, photophysical measurements indicate the formation of sub-bands in the optical bandgap which is beneficial for exciton splitting. Moreover, the new bands can mediate hole transfer to the electrolyte, thus improving the photooxidation activity. The utilization of high temperature solvent as the polymerization medium opens new opportunities for the significant improvement of carbon nitride films toward an efficient photoactive material for various applications.}, language = {en} } @article{XuBrennerChenetal.2014, author = {Xu, Jingsan and Brenner, Thomas J. K. and Chen, Zupeng and Neher, Dieter and Antonietti, Markus and Shalom, Menny}, title = {Upconversion-agent induced improvement of g-C3N4 photocatalyst under visible light}, series = {ACS applied materials \& interfaces}, volume = {6}, journal = {ACS applied materials \& interfaces}, number = {19}, publisher = {American Chemical Society}, address = {Washington}, issn = {1944-8244}, doi = {10.1021/am5051263}, pages = {16481 -- 16486}, year = {2014}, abstract = {Herein, we report the use of upconversion agents to modify graphite carbon nitride (g-C3N4) by direct thermal condensation of a mixture of ErCl3 center dot 6H(2)O and the supramolecular precursor cyanuric acid-melamine. We show the enhancement of g-C3N4 photoactivity after Er3+ doping by monitoring the photodegradation of Rhodamine B dye under visible light. The contribution of the upconversion agent is demonstrated by measurements using only a red laser. The Er3+ doping alters both the electronic and the chemical properties of g-C3N4. The Er3+ doping reduces emission intensity and lifetime, indicating the formation of new, nonradiative deactivation pathways, probably involving charge-transfer processes.}, language = {en} } @article{XuBrennerChabanneetal.2014, author = {Xu, Jingsan and Brenner, Thomas J. K. and Chabanne, Laurent and Neher, Dieter and Antonietti, Markus and Shalom, Menny}, title = {Liquid-Based growth of polymeric carbon nitride layers and their use in a mesostructured polymer solar cell with V-oc exceeding 1 V}, series = {Journal of the American Chemical Society}, volume = {136}, journal = {Journal of the American Chemical Society}, number = {39}, publisher = {American Chemical Society}, address = {Washington}, issn = {0002-7863}, doi = {10.1021/ja508329c}, pages = {13486 -- 13489}, year = {2014}, abstract = {Herein we report a general liquid-mediated pathway for the growth of continuous polymeric carbon nitride (C3N4) thin films. The deposition method consists of the use of supramolecular complexes that transform to the liquid state before direct thermal condensation into C3N4 solid films. The resulting films exhibit continuous porous C3N4 networks on various substrates. Moreover, the optical absorption can be easily tuned to cover the solar spectrum by the insertion of an additional molecule into the starting complex. The strength of the deposition method is demonstrated by the use of the C3N4 layer as the electron acceptor in a polymer solar cell that exhibits a remarkable open-circuit voltage exceeding 1 V. The easy, safe, and direct synthesis of carbon nitride in a continuous layered architecture on different functional substrates opens new possibilities for the fabrication of many energy-related devices.}, language = {en} } @article{ShalomInalNeheretal.2014, author = {Shalom, Menny and Inal, Sahika and Neher, Dieter and Antonietti, Markus}, title = {SiO2/carbon nitride composite materials: The role of surfaces for enhanced photocatalysis}, series = {Catalysis today : a serial publication dealing with topical themes in catalysis and related subjects}, volume = {225}, journal = {Catalysis today : a serial publication dealing with topical themes in catalysis and related subjects}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0920-5861}, doi = {10.1016/j.cattod.2013.12.013}, pages = {185 -- 190}, year = {2014}, abstract = {The effect of SiO2 nanoparticles on carbon nitride (C3N4) photoactivity performance is described. The composite SiO2-C3N4 materials exhibit a higher activity in the photo degradation of RhB dye. A detailed analysis of the chemical and optical properties of the composite C3N4 materials shows that the photo activity increases with higher SiO2 concentration. We found out that the presence of SiO2 nanoparticles strongly affects the fluorescence intensity of the matrix and life time by the creation of new energy states for charge transfer within the C3N4. Furthermore, the use of SiO2 in the synthesis of C3N4 leads to new morphology with higher surface area which results in another, secondary improvement of C3N4 photoactivity. The effect of different surfaces within C3N4 on its chemical and electronic properties is discussed and a tentative mechanism is proposed. The utilization of SiO2 nanoparticles improves both photophysical and chemical properties of C3N4 and opens new possibilities for further enhancement of C3N4 catalytic properties by the formation of composites with many other materials.}, language = {en} } @article{ShalomGuttentagFettkenhaueretal.2014, author = {Shalom, Menny and Guttentag, Miguel and Fettkenhauer, Christian and Inal, Sahika and Neher, Dieter and Llobet, Antoni and Antonietti, Markus}, title = {In situ formation of heterojunctions in modified graphitic carbon nitride: synthesis and noble metal free photocatalysis}, series = {Chemistry of materials : a publication of the American Chemical Society}, volume = {26}, journal = {Chemistry of materials : a publication of the American Chemical Society}, number = {19}, publisher = {American Chemical Society}, address = {Washington}, issn = {0897-4756}, doi = {10.1021/cm503258z}, pages = {5812 -- 5818}, year = {2014}, abstract = {Herein, we report the facile synthesis of an efficient roll-like carbon nitride (C3N4) photocatalyst for hydrogen production using a supramolecular complex composed of cyanuric acid, melamine, and barbituric acid as the starting monomers. Optical and photocatalytic investigations show, along with the known red shift of absorption into the visible region, that the insertion of barbituric acid results in the in situ formation of in-plane heterojuctions, which enhance the charge separation process under illumination. Moreover, platinum as the standard cocatalyst in photocatalysis could be successfully replaced with first row transition metal salts and complexes under retention of 50\% of the catalytic activity. Their mode of deposition and interaction with the semiconductor was studied in detail. Utilization of the supramolecular approach opens new opportunities to manipulate the charge transfer process within carbon nitride with respect to the design of a more efficient carbon nitride photocatalyst with controlled morphology and optical properties.}, language = {en} } @article{JordanFechlerXuetal.2015, author = {Jordan, Thomas and Fechler, Nina and Xu, Jingsan and Brenner, Thomas J. K. and Antonietti, Markus and Shalom, Menny}, title = {"Caffeine Doping" of Carbon/Nitrogen-Based Organic Catalysts: Caffeine as a Supramolecular Edge Modifier for the Synthesis of Photoactive Carbon Nitride Tubes}, series = {ChemCatChem : heterogeneous \& homogeneous \& bio- \& nano-catalysis ; a journal of ChemPubSoc Europe}, volume = {7}, journal = {ChemCatChem : heterogeneous \& homogeneous \& bio- \& nano-catalysis ; a journal of ChemPubSoc Europe}, number = {18}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1867-3880}, doi = {10.1002/cctc.201500343}, pages = {2826 -- 2830}, year = {2015}, abstract = {An alternative method for the structure tuning of carbon nitride materials by using a supramolecular approach in combination with caffeine as lining-agent is described. The self-assembly of the precursor complex consisting of melamine and cyanuric acid can be controlled by this doping molecule in terms of morphology, electronic, and photophysical properties. Caffeine is proposed to insert as an edge-molecule eventually leading to hollow tube-like carbon nitride structures with improved efficiency of charge formation. Compared to the bulk carbon nitride, the caffeine-doped analogue possesses a higher photocatalytic activity for the degradation of rhodamineB dye. Furthermore, this approach is also shown to be suitable for the modification of carbon nitride electrodes.}, language = {en} }