@article{YanJosefHuangetal.2019, author = {Yan, Runyu and Josef, Elinor and Huang, Haijian and Leus, Karen and Niederberger, Markus and Hofmann, Jan P. and Walczak, Ralf and Antonietti, Markus and Oschatz, Martin}, title = {Understanding the charge storage mechanism to achieve high capacity and fast ion storage in sodium-ion capacitor anodes by using electrospun nitrogen-doped carbon fibers}, series = {Advanced functional materials}, volume = {29}, journal = {Advanced functional materials}, number = {26}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1616-301X}, doi = {10.1002/adfm.201902858}, pages = {13}, year = {2019}, abstract = {Microporous nitrogen-rich carbon fibers (HAT-CNFs) are produced by electrospinning a mixture of hexaazatriphenylene-hexacarbonitrile (HAT-CN) and polyvinylpyrrolidone and subsequent thermal condensation. Bonding motives, electronic structure, content of nitrogen heteroatoms, porosity, and degree of carbon stacking can be controlled by the condensation temperature due to the use of the HAT-CN with predefined nitrogen binding motives. The HAT-CNFs show remarkable reversible capacities (395 mAh g(-1) at 0.1 A g(-1)) and rate capabilities (106 mAh g(-1) at 10 A g(-1)) as an anode material for sodium storage, resulting from the abundant heteroatoms, enhanced electrical conductivity, and rapid charge carrier transport in the nanoporous structure of the 1D fibers. HAT-CNFs also serve as a series of model compounds for the investigation of the contribution of sodium storage by intercalation and reversible binding on nitrogen sites at different rates. There is an increasing contribution of intercalation to the charge storage with increasing condensation temperature which becomes less active at high rates. A hybrid sodium-ion capacitor full cell combining HAT-CNF as the anode and salt-templated porous carbon as the cathode provides remarkable performance in the voltage range of 0.5-4.0 V (95 Wh kg(-1) at 0.19 kW kg(-1) and 18 Wh kg(-1) at 13 kW kg(-1)).}, language = {en} } @misc{MenSiebenbuergerQiuetal.2013, author = {Men, Yongjun and Siebenb{\"u}rger, Miriam and Qiu, Xunlin and Antonietti, Markus and Yuan, Jiayin}, title = {Low fractions of ionic liquid or poly(ionic liquid) can activate polysaccharide biomass into shaped, flexible and fire-retardant porous carbons}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-95250}, pages = {11887 -- 11887}, year = {2013}, abstract = {Sugar-based molecules and polysaccharide biomass can be turned into porous functional carbonaceous products at comparably low temperatures of 400 °C under a nitrogen atmosphere in the presence of an ionic liquid (IL) or a poly(ionic liquid) (PIL). The IL and PIL act as "activation agents" with own structural contribution, and effectively promote the conversion and pore generation in the biomaterials even at a rather low doping ratio (7 wt\%). In addition, this "induced carbonization" and pore forming phenomenon enables the preservation of the biotemplate shape to the highest extent and was employed to fabricate shaped porous carbonaceous materials from carbohydrate-based biotemplates, exemplified here with cellulose filter membranes, coffee filter paper and natural cotton. These carbonized hybrids exhibit comparably good mechanical properties, such as bendability of membranes or shape recovery of foams. Moreover, the nitrogen atoms incorporated in the final products from the IL/PIL precursors further improve the oxidation stability in the fire-retardant tests.}, 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{ZhaoDunlopQiuetal.2014, author = {Zhao, Qiang and Dunlop, John William Chapman and Qiu, Xunlin and Huang, Feihe and Zhang, Zibin and Heyda, Jan and Dzubiella, Joachim and Antonietti, Markus and Yuan, Jiayin}, title = {An instant multi-responsive porous polymer actuator driven by solvent molecule sorption}, series = {Nature Communications}, volume = {5}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/ncomms5293}, pages = {8}, year = {2014}, abstract = {Fast actuation speed, large-shape deformation and robust responsiveness are critical to synthetic soft actuators. A simultaneous optimization of all these aspects without trade-offs remains unresolved. Here we describe porous polymer actuators that bend in response to acetone vapour (24 kPa, 20 degrees C) at a speed of an order of magnitude faster than the state-of-the-art, coupled with a large-scale locomotion. They are meanwhile multi-responsive towards a variety of organic vapours in both the dry and wet states, thus distinctive from the traditional gel actuation systems that become inactive when dried. The actuator is easy-to-make and survives even after hydrothermal processing (200 degrees C, 24 h) and pressing-pressure (100 MPa) treatments. In addition, the beneficial responsiveness is transferable, being able to turn 'inert' objects into actuators through surface coating. This advanced actuator arises from the unique combination of porous morphology, gradient structure and the interaction between solvent molecules and actuator materials.}, 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{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{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{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} } @article{BrosnanSchlaadAntonietti2015, author = {Brosnan, Sarah M. and Schlaad, Helmut and Antonietti, Markus}, title = {Aqueous Self-Assembly of Purely Hydrophilic Block Copolymers into Giant Vesicles}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, volume = {54}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, number = {33}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1433-7851}, doi = {10.1002/anie.201502100}, pages = {9715 -- 9718}, year = {2015}, abstract = {Self-assembly of macromolecules is fundamental to life itself, and historically, these systems have been primitively mimicked by the development of amphiphilic systems, driven by the hydrophobic effect. Herein, we demonstrate that self-assembly of purely hydrophilic systems can be readily achieved with similar ease and success. We have synthesized double hydrophilic block copolymers from polysaccharides and poly(ethylene oxide) or poly(sarcosine) to yield high molar mass diblock copolymers through oxime chemistry. These hydrophilic materials can easily assemble into nanosized (<500nm) and microsized (>5m) polymeric vesicles depending on concentration and diblock composition. Because of the solely hydrophilic nature of these materials, we expect them to be extraordinarily water permeable systems that would be well suited for use as cellular mimics.}, language = {en} } @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{ChenSavateevPronkinetal.2017, author = {Chen, Zupeng and Savateev, Aleksandr and Pronkin, Sergey and Papaefthimiou, Vasiliki and Wolff, Christian Michael and Willinger, Marc Georg and Willinger, Elena and Neher, Dieter and Antonietti, Markus and Dontsova, Dariya}, title = {"The Easier the Better" Preparation of Efficient Photocatalysts-Metastable Poly(heptazine imide) Salts}, series = {Advanced materials}, volume = {29}, journal = {Advanced materials}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0935-9648}, doi = {10.1002/adma.201700555}, pages = {21800 -- 21806}, year = {2017}, abstract = {Cost-efficient, visible-light-driven hydrogen production from water is an attractive potential source of clean, sustainable fuel. Here, it is shown that thermal solid state reactions of traditional carbon nitride precursors (cyanamide, melamine) with NaCl, KCl, or CsCl are a cheap and straightforward way to prepare poly(heptazine imide) alkali metal salts, whose thermodynamic stability decreases upon the increase of the metal atom size. The chemical structure of the prepared salts is confirmed by the results of X-ray photoelectron and infrared spectroscopies, powder X-ray diffraction and electron microscopy studies, and, in the case of sodium poly(heptazine imide), additionally by atomic pair distribution function analysis and 2D powder X-ray diffraction pattern simulations. In contrast, reactions with LiCl yield thermodynamically stable poly(triazine imides). Owing to the metastability and high structural order, the obtained heptazine imide salts are found to be highly active photo-catalysts in Rhodamine B and 4-chlorophenol degradation, and Pt-assisted sacrificial water reduction reactions under visible light irradiation. The measured hydrogen evolution rates are up to four times higher than those provided by a benchmark photocatalyst, mesoporous graphitic carbon nitride. Moreover, the products are able to photocatalytically reduce water with considerable reaction rates, even when glycerol is used as a sacrificial hole scavenger.}, language = {en} } @article{SungKochovskiZhangetal.2017, author = {Sung, Jian-Ke and Kochovski, Zdravko and Zhang, Wei-Yi and Kirmse, Holm and Lu, Yan and Antonietti, Markus and Yuan, Jiayin}, title = {General Synthetic Route toward Highly Dispersed Metal Clusters Enabled by Poly(ionic liquid)s}, series = {Journal of the American Chemical Society}, volume = {139}, journal = {Journal of the American Chemical Society}, publisher = {American Chemical Society}, address = {Washington}, issn = {0002-7863}, doi = {10.1021/jacs.7b03357}, pages = {8971 -- 8976}, year = {2017}, abstract = {The ability to synthesize a broad spectrum of metal clusters (MCs) with their size controllable on a subnanometer scale presents an enticing prospect for exploring nanosize-dependent properties. Here we report an innovative design of a capping agent from a polytriazolium poly(ionic liquid) (PIL) in a vesicular form in solution that allows for crafting a variety of MCs including transition metals, noble metals, and their bimetallic alloy with precisely controlled sizes (similar to 1 nm) and record-high catalytic performance. The ultrastrong stabilization power is a result of an unusual synergy between the conventional binding sites in the heterocyclic cations in PIL and an in situ generated polycarbene structure induced simultaneously to the reduction reaction.}, language = {en} } @article{QinHeilSchmidtetal.2019, author = {Qin, Qing and Heil, T. and Schmidt, J. and Schmallegger, Max and Gescheidt, Georg and Antonietti, Markus and Oschatz, Martin}, title = {Electrochemical Fixation of Nitrogen and Its Coupling with Biomass Valorization with a Strongly Adsorbing and Defect Optimized Boron-Carbon-Nitrogen Catalyst}, series = {ACS Applied Energy Materials}, volume = {2}, journal = {ACS Applied Energy Materials}, number = {11}, publisher = {American Chemical Society}, address = {Washington}, issn = {2574-0962}, doi = {10.1021/acsaem.9b01852}, pages = {8359 -- 8365}, year = {2019}, abstract = {The electrochemical conversion of low-cost precursors into high-value chemicals using renewably generated electricity is a promising approach to build up an environmentally friendly energy cycle, including a storage element. The large-scale implementation of such process can, however, only be realized by the design of cost-effective electrocatalysts with high efficiency and highest stability. Here, we report the synthesis of N and B codoped porous carbons. The constructed B-N motives combine abundant unpaired electrons and frustrated Lewis pairs (FLPs). They result in desirable performance for electrochemical N-2 reduction reaction (NRR) and electrooxidation of 5-hydroxymethylfurfural (HMF) in the absence of any metal cocatalyst. A maximum Faradaic efficiency of 15.2\% with a stable NH3 production rate of 21.3 mu g h(-1) mg(-1) is obtained in NRR. Besides, 2,5-furandicarboxylic acid (FDCA) is first obtained by using non-metalbased electrocatalysts at a conversion of 71\% and with yield of 57\%. Gas adsorption experiments elucidate the relationship between the structure and the ability of the catalysts to activate the substrate molecules. This work opens up deep insights for the rational design of non-metal-based catalysts for potential electrocatalytic applications and the possible enhancement of their activity by the introduction of FLPs and point defects at grain boundaries.}, language = {en} } @article{WalczakSavateevHeskeetal.2019, author = {Walczak, Ralf and Savateev, Aleksandr and Heske, Julian and Tarakina, Nadezda V. and Sahoo, Sudhir and Epping, Jan D. and Kuehne, Thomas D. and Kurpil, Bogdan and Antonietti, Markus and Oschatz, Martin}, title = {Controlling the strength of interaction between carbon dioxide and nitrogen-rich carbon materials by molecular design}, series = {Sustainable energy \& fuels}, volume = {3}, journal = {Sustainable energy \& fuels}, number = {10}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2398-4902}, doi = {10.1039/c9se00486f}, pages = {2819 -- 2827}, year = {2019}, abstract = {Thermal treatment of hexaazatriphenylene-hexacarbonitrile (HAT-CN) in the temperature range from 500 degrees C to 700 degrees C leads to precise control over the degree of condensation, and thus atomic construction and porosity of the resulting C2N-type materials. Depending on the condensation temperature of HAT-CN, nitrogen contents of more than 30 at\% can be reached. In general, these carbons show adsorption properties which are comparable to those known for zeolites but their pore size can be adjusted over a wider range. At condensation temperatures of 525 degrees C and below, the uptake of nitrogen gas remains negligible due to size exclusion, but the internal pores are large and polarizing enough that CO2 can still adsorb on part of the internal surface. This leads to surprisingly high CO2 adsorption capacities and isosteric heat of adsorption of up to 52 kJ mol(-1). Theoretical calculations show that this high binding enthalpy arises from collective stabilization effects from the nitrogen atoms in the C2N layers surrounding the carbon atom in the CO2 molecule and from the electron acceptor properties of the carbon atoms from C2N which are in close proximity to the oxygen atoms in CO2. A true CO2 molecular sieving effect is achieved for the first time in such a metal-free organic material with zeolite-like properties, showing an IAST CO2/N-2 selectivity of up to 121 at 298 K and a N-2/CO2 ratio of 90/10 without notable changes in the CO2 adsorption properities over 80 cycles.}, language = {en} } @article{LaiFengHeietal.2019, author = {Lai, Feili and Feng, Jianrui and Hei, Tobias and Wang, Gui-Chang and Adler, Peter and Antonietti, Markus and Oschatz, Martin}, title = {Strong metal oxide-support interactions in carbon/hematite nanohybrids activate novel energy storage modes for ionic liquid-based supercapacitors}, series = {Energy Storage Materials}, volume = {20}, journal = {Energy Storage Materials}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8297}, doi = {10.1016/j.ensm.2019.04.035}, pages = {188 -- 195}, year = {2019}, abstract = {Strong metal oxide-support interaction is crucial to activate high energy storage modes of carbon-supported hybrid electrodes in ionic liquid-based supercapacitors. Although it is known that conductive supports can influence the electrochemical properties of metal oxides, insights into how metal oxide-support interactions can be exploited to optimize joint energy storage properties are lacking. We report the junction between alpha-Fe2O3 nanosplotches and phosphorus-doped ordered mesoporous carbon (CMK-3-P) with strong covalent anchoring of the metal oxide. The oxide-carbon interaction in CMK-3-P-Fe2O3 is strengthening the junction and charge transfer between Fe2O3 and CMK-3-P. It enhances energy storage by intensifying the interaction between ionic liquid ions and the surface of the electrode. Density functional theory simulations reveal that the strong metal oxide-support interaction increases the adsorption energy of ionic liquid to -4.77 eV as compared to -3.85 eV for a CMK-3Fe(2)O(3) hybrid with weaker binding. In spite of the lower specific surface area and apparently similar energy storage mode, the CMK-3-P-Fe2O3 exhibits superior electrical double-layer capacitor performance with a specific capacitance of 179 F g(-1) at 2 mV s(-1) (0-3.5 V) in comparison to Fe2O3-free CMK-3 and CMK-3-P reference materials. This principle for design of hybrid electrodes can be applicable for future rational design of stable metal oxide-support electrodes for advanced energy storage.}, language = {en} } @misc{AntoniettiLopezSalasPrimo2018, author = {Antonietti, Markus and Lopez-Salas, Nieves and Primo, Ana}, title = {Adjusting the Structure and Electronic Properties of Carbons for Metal-Free Carbocatalysis of Organic Transformations}, series = {Advanced materials}, volume = {31}, journal = {Advanced materials}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0935-9648}, doi = {10.1002/adma.201805719}, pages = {15}, year = {2018}, abstract = {Carbon nanomaterials doped with some other lightweight elements were recently described as powerful, heterogeneous, metal-free organocatalysts, adding to their high performance in electrocatalysis. Here, recent observations in traditional catalysis are reviewed, and the underlying reaction mechanisms of the catalyzed organic transformations are explored. In some cases, these are due to specific active functional sites, but more generally the catalytic activity relates to collective properties of the conjugated nanocarbon frameworks and the electron transfer from and to the catalytic centers and substrates. It is shown that the !earnings are tightly related to those of electrocatalysis; i.e., the search for better electrocatalysts also improves chemocatalysis, and vice versa. Carbon-carbon heterojunction effects and some perspectives on future possibilities are discussed at the end.}, language = {en} } @article{LeeHwangSchildeetal.2018, author = {Lee, Hui-Chun and Hwang, Jongkook and Schilde, Uwe and Antonietti, Markus and Matyjaszewski, Krzysztof and Schmidt, Bernhard V. K. J.}, title = {Toward ultimate control of radical polymerization}, series = {Chemistry of materials : a publication of the American Chemical Society}, volume = {30}, journal = {Chemistry of materials : a publication of the American Chemical Society}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {0897-4756}, doi = {10.1021/acs.chemmater.8b00546}, pages = {2983 -- 2994}, year = {2018}, abstract = {Herein, an approach via combination of confined porous textures and reversible deactivation radical polymerization techniques is proposed to advance synthetic polymer chemistry, i.e., a connection of metal-organic frameworks (MOFs) and activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). Zn-2(benzene-1,4-dicarboxylate)2(1,4-diazabicyclo[2.2.2]-octane) [Zn-2(bdc)(2)(dabco)] is utilized as a reaction environment for polymerization of various methacrylate monomers (methyl, ethyl, benzyl, and isobornyl methacrylate) in a confined nanochannel, resulting in polymers with control over dispersity, end functionalities, and tacticity with respect to distinct molecular size. To refine and reconsolidate the compartmentation effect on polymer regularity, initiator-functionalized Zn MOF was synthesized via cocrystallization with an initiator-functionalized ligand, 2-(2-bromo-2-methylpropanamido)-1,4-benzenedicarboxylate (Brbdc), in different ratios (10\%, 20\%, and 50\%). Through the embedded initiator, surface-initiated ARGET ATRP was directly initiated from the walls of the nanochannels. The obtained polymers had a high molecular weight up to 392 000. Moreover, a significant improvement in end-group functionality and stereocontrol was observed, entailing polymers with obvious increments in isotacticity. The results highlight a combination of MOFs and ATRP that is a promising and universal methodology to prepare various polymers with high molecular weight exhibiting well-defined uniformity in chain length and microstructure as well as the preserved chain-end functionality.}, language = {en} } @article{YoukHofmannBadamdorjetal.2020, author = {Youk, Sol and Hofmann, Jan P. and Badamdorj, Bolortuya and Volkel, Antje and Antonietti, Markus and Oschatz, Martin}, title = {Controlling pore size and pore functionality in sp(2)-conjugated microporous materials by precursor chemistry and salt templating}, series = {Journal of materials chemistry : A, Materials for energy and sustainability}, volume = {8}, journal = {Journal of materials chemistry : A, Materials for energy and sustainability}, number = {41}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2050-7488}, doi = {10.1039/d0ta05856d}, pages = {21680 -- 21689}, year = {2020}, abstract = {The synthesis of sp(2)-conjugated, heteroatom-rich, "carbonaceous" materials from economically feasible raw materials and salt templates is reported. Low cost citrazinic acid (2,6-dihydroxy-4-pyridinecarboxylic acid) and melamine are used as components to form a microporous, amorphous framework, where edges of the covalent frameworks are tightly terminated with nitrogen and oxygen moieties. ZnCl2 as the porogen stabilizes structural microporosity as well as nitrogen and oxygen heteroatoms up to comparably high condensation temperatures of 750 and 950 degrees C. The specific surface area up to 1265 m(2) g(-1) is mainly caused by micropores and typical of heteroatom-rich carbon materials with such structural porosity. The unusually high heteroatom content reveals that the edges and pores of the covalent structures are tightly lined with heteroatoms, while C-C or C-H bonds are expected to have a minor contribution as compared to typical carbon materials without or with minor content of heteroatoms. Adsorption of water vapor and carbon dioxide are exemplarily chosen to illustrate the impact of this heteroatom functionalization under salt-templating conditions on the adsorption properties of the materials. 27.10 mmol g(-1) of H2O uptake (at p/p(0) = 0.9) can be achieved, which also proves the very hydrophilic character of the pore walls, while the maximum CO2 uptake (at 273 K) is 5.3 mmol g(-1). At the same time the CO2/N-2 adsorption selectivity at 273 K can reach values of up to 60. All these values are beyond those of ordinary high surface area carbons, also differ from those of N-doped carbons, and are much closer to those of organized framework species, such as C2N.}, 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{IlicTsoukaPerovicetal.2020, author = {Ilic, Ivan K. and Tsouka, Alexandra and Perovic, Milena and Hwang, Jinyeon and Heil, Tobias and L{\"o}ffler, Felix F. and Oschatz, Martin and Antonietti, Markus and Liedel, Clemens}, title = {Sustainable cathodes for Lithium-ion energy storage devices based on tannic acid-toward ecofriendly energy storage}, series = {Advanced sustainable systems}, volume = {5}, journal = {Advanced sustainable systems}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2366-7486}, doi = {10.1002/adsu.202000206}, pages = {8}, year = {2020}, abstract = {The use of organic materials with reversible redox activity holds enormous potential for next-generation Li-ion energy storage devices. Yet, most candidates are not truly sustainable, i.e., not derived from renewable feedstock or made in benign reactions. Here an attempt is reported to resolve this issue by synthesizing an organic cathode material from tannic acid and microporous carbon derived from biomass. All constituents, including the redox-active material and conductive carbon additive, are made from renewable resources. Using a simple, sustainable fabrication method, a hybrid material is formed. The low cost and ecofriendly material shows outstanding performance with a capacity of 108 mAh g(-1) at 0.1 A g(-1) and low capacity fading, retaining approximately 80\% of the maximum capacity after 90 cycles. With approximately 3.4 V versus Li+/Li, the cells also feature one of the highest reversible redox potentials reported for biomolecular cathodes. Finally, the quinone-catecholate redox mechanism responsible for the high capacity of tannic acid is confirmed by electrochemical characterization of a model compound similar to tannic acid but without catecholic groups.}, language = {en} } @article{AlNajiSchlaadAntonietti2020, author = {Al-Naji, Majd and Schlaad, Helmut and Antonietti, Markus}, title = {New (and old) monomers from biorefineries to make polymer chemistry more sustainable}, series = {Macromolecular rapid communications}, volume = {42}, journal = {Macromolecular rapid communications}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1022-1336}, doi = {10.1002/marc.202000485}, pages = {11}, year = {2020}, abstract = {This opinion article describes recent approaches to use the "biorefinery" concept to lower the carbon footprint of typical mass polymers, by replacing parts of the fossil monomers with similar or even the same monomer made from regrowing dendritic biomass. Herein, the new and green catalytic synthetic routes are for lactic acid (LA), isosorbide (IS), 2,5-furandicarboxylic acid (FDCA), and p-xylene (pXL). Furthermore, the synthesis of two unconventional lignocellulosic biomass derivable monomers, i.e., alpha-methylene-gamma-valerolactone (MeGVL) and levoglucosenol (LG), are presented. All those have the potential to enter in a cost-effective way, also the mass market and thereby recover lost areas for polymer materials. The differences of catalytic unit operations of the biorefinery are also discussed and the challenges that must be addressed along the synthesis path of each monomers.}, language = {en} } @article{CazellesLalaouiHartmannetal.2016, author = {Cazelles, R. and Lalaoui, N. and Hartmann, Tobias and Leimk{\"u}hler, Silke and Wollenberger, Ursula and Antonietti, Markus and Cosnier, S.}, title = {Ready to use bioinformatics analysis as a tool to predict immobilisation strategies for protein direct electron transfer (DET)}, series = {Polymer : the international journal for the science and technology of polymers}, volume = {85}, journal = {Polymer : the international journal for the science and technology of polymers}, publisher = {Elsevier}, address = {Oxford}, issn = {0956-5663}, doi = {10.1016/j.bios.2016.04.078}, pages = {90 -- 95}, year = {2016}, language = {en} } @article{ChenYanOschatzetal.2020, author = {Chen, Lu and Yan, Runyu and Oschatz, Martin and Jiang, Lei and Antonietti, Markus and Xiao, Kai}, title = {Ultrathin 2D graphitic carbon nitride on metal films}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, volume = {59}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, number = {23}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1433-7851}, doi = {10.1002/anie.202000314}, pages = {9067 -- 9073}, year = {2020}, abstract = {Efficient and low-cost anode materials for the sodium-ion battery are highly desired to enable more economic energy storage. Effects on an ultrathin carbon nitride film deposited on a copper metal electrode are presented. The combination of effects show an unusually high capacity to store sodium metal. The g-C3N4 film is as thin as 10 nm and can be fabricated by an efficient, facile, and general chemical-vapor deposition method. A high reversible capacity of formally up to 51 Ah g(-1) indicates that the Na is not only stored in the carbon nitride as such, but that carbon nitride activates also the metal for reversible Na-deposition, while forming at the same time an solid electrolyte interface layer avoiding direct contact of the metallic phase with the liquid electrolyte.}, language = {en} } @article{ZhangSpitzAntoniettietal.2005, author = {Zhang, T. and Spitz, Christian and Antonietti, Markus and Faul, C. F.}, title = {Highly photoluminescent polyoxometaloeuropate-surfactant complexes by ionic self-assembly}, year = {2005}, abstract = {Facile organization of the inorganic sandwiched heteropolytungstomolybdate K-13[Eu(SiW9Mo2O39)(2)] (E) into highly ordered supramolecular nanostructured materials by complexation with a series of cationic surfactants is achieved by the ionic self-assembly (ISA) route. The structure and phase behavior of the complexes were examined by IR spectroscopy, differential scanning calorimetry, optical microscopy, and small- and wide-angle X-ray scattering. This class of materials shows a number of interesting physicochemical properties, namely liquid-crystalline phases (both thermotropic and lyotropic) and strong photoluminescence. The photophysical behavior (fluorescence spectra, fluorescence lifetimes, fluorescence quantum yield) of the complexes differs widely in solid powders, films, and solutions. The amphiphilic cationic surfactants not only play a structural role but also have a strong influence on the photophysical properties of E. The photophysical behavior of E can in this way be easily modified by its organizational motifs}, language = {en} } @article{SonnenburgAdelhelmAntoniettietal.2006, author = {Sonnenburg, Kirstin and Adelhelm, Philipp and Antonietti, Markus and Smarsly, Bernd and N{\"o}ske, Robert and Strauch, Peter}, title = {Synthesis and characterization of SiC materials with hierarchical porosity obtained by replication techniques}, doi = {10.1039/B604819F}, year = {2006}, abstract = {Porous silicon carbide monoliths were obtained using the infiltration of preformed SiO2 frameworks with appropriate carbon precursors such as mesophase pitch. The initial SiO2 monoliths possessed a hierarchical pore system, composed of an interpenetrating bicontinuous macropore structure and 13 nm mesopores confined in the macropore walls. After carbonization, further heat treatment at ca. 1400 degrees C resulted in the formation of a SiC-SiO2 composite, which was converted into a porous SiC monolith by post-treatment with ammonium fluoride solution. The resulting porous SiC featured high crystallinity, high chemical purity and showed a surface area of 280 m(2) g(-1) and a pore volume of 0.8 ml g(-1)}, language = {en} } @article{MenSiebenbuergerQiuetal.2013, author = {Men, Yongiun and Siebenb{\"u}rger, Miriam and Qiu, Xunlin and Antonietti, Markus and Yuan, Jiayin}, title = {Low fractions of ionic liquid or poly(ionic liquid) can activate polysaccaride biomass into shaped, flexible and fire-retardant porous carbons}, doi = {10.1039/c3ta12302b}, year = {2013}, abstract = {Sugar-based molecules and polysaccharide biomass can be turned into porous functional carbonaceous products at comparably low temperatures of 400 °C under a nitrogen atmosphere in the presence of an ionic liquid (IL) or a poly(ionic liquid) (PIL). The IL and PIL act as "activation agents" with own structural contribution, and effectively promote the conversion and pore generation in the biomaterials even at a rather low doping ratio (7 wt\%). In addition, this "induced carbonization" and pore forming phenomenon enables the preservation of the biotemplate shape to the highest extent and was employed to fabricate shaped porous carbonaceous materials from carbohydrate-based biotemplates, exemplified here with cellulose filter membranes, coffee filter paper and natural cotton. These carbonized hybrids exhibit comparably good mechanical properties, such as bendability of membranes or shape recovery of foams. Moreover, the nitrogen atoms incorporated in the final products from the IL/PIL precursors further improve the oxidation stability in the fire-retardant tests.}, language = {en} } @article{MenSiebenbuergerQiuetal.2013, author = {Men, Yongjun and Siebenb{\"u}rger, Miriam and Qiu, Xunlin and Antonietti, Markus and Yuan, Jiayin}, title = {Low fractions of ionic liquid or poly(ionic liquid) can activate polysaccharide biomass into shaped, flexible and fire-retardant porous carbons}, series = {Journal of materials chemistry : A, Materials for energy and sustainability}, volume = {1}, journal = {Journal of materials chemistry : A, Materials for energy and sustainability}, number = {38}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2050-7488}, doi = {10.1039/c3ta12302b}, pages = {11887 -- 11893}, year = {2013}, abstract = {Sugar-based molecules and polysaccharide biomass can be turned into porous functional carbonaceous products at comparably low temperatures of 400 degrees C under a nitrogen atmosphere in the presence of an ionic liquid (IL) or a poly(ionic liquid) (PIL). The IL and PIL act as "activation agents" with own structural contribution, and effectively promote the conversion and pore generation in the biomaterials even at a rather low doping ratio (7 wt\%). In addition, this "induced carbonization" and pore forming phenomenon enables the preservation of the biotemplate shape to the highest extent and was employed to fabricate shaped porous carbonaceous materials from carbohydrate-based biotemplates, exemplified here with cellulose filter membranes, coffee filter paper and natural cotton. These carbonized hybrids exhibit comparably good mechanical properties, such as bendability of membranes or shape recovery of foams. Moreover, the nitrogen atoms incorporated in the final products from the IL/PIL precursors further improve the oxidation stability in the fire-retardant tests.}, language = {en} } @article{ShalomInalFettkenhaueretal.2013, author = {Shalom, Menny and Inal, Sahika and Fettkenhauer, Christian and Neher, Dieter and Antonietti, Markus}, title = {Improving Carbon Nitride Photocatalysis by Supramolecular Preorganization of Monomers}, series = {Journal of the American Chemical Society}, volume = {135}, journal = {Journal of the American Chemical Society}, number = {19}, publisher = {American Chemical Society}, address = {Washington}, issn = {0002-7863}, doi = {10.1021/ja402521s}, pages = {7118 -- 7121}, year = {2013}, abstract = {Here we report a new and simple synthetic pathway to form ordered, hollow carbon nitride structures, using a cyanuric acid melamine (CM) complex in ethanol as a starting product. A detailed analysis of the optical and photocatalytic properties shows that optimum hollow carbon nitride structures are formed after 8 h of condensation. For this condensation time, we find a significantly reduced fluorescence intensity and lifetime, indicating the formation of new, nonradiative deactivation pathways, probably involving charge-transfer processes. Enhanced charge transfer is seen as well from a drastic increase of the photocatalytic activity in the degradation of rhodamine B dye, which is shown to proceed via photoinduced hole transfer. Moreover, we show that various CM morphologies can be obtained using different solvents, which leads to diverse ordered carbon nitride architectures. In all cases, the CM-C3N4 structures exhibited superior photocatalytic activity compared to the bulk material. The utilization of CM hydrogen-bonded complexes opens new opportunities for the significant improvement of carbon nitride synthesis, structure, and optical properties toward an efficient photoactive material for catalysis.}, 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: a combined first principles and semiempirical study}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {16}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {30}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, 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 H-2 production O-2 evolution is only possible in the presence of oxidation cocatalysts.}, language = {en} } @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} } @article{HarmanliTarakinaAntoniettietal.2021, author = {Harmanli, İpek and Tarakina, Nadezda and Antonietti, Markus and Oschatz, Martin}, title = {"Giant" nitrogen uptake in ionic liquids confined in carbon pores}, series = {Journal of the American Chemical Society}, volume = {143}, journal = {Journal of the American Chemical Society}, number = {25}, publisher = {American Chemical Society}, address = {Washington}, issn = {0002-7863}, doi = {10.1021/jacs.1c00783}, pages = {9377 -- 9384}, year = {2021}, abstract = {Ionic liquids are well known for their high gas absorption capacity. It is shown that this is not a solvent constant, but can be enhanced by another factor of 10 by pore confinement, here of the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate (EmimOAc) in the pores of carbon materials. A matrix of four different carbon compounds with micro- and mesopores as well as with and without nitrogen doping is utilized to investigate the influence of the carbons structure on the nitrogen uptake in the pore-confined EmimOAc. In general, the absorption is most improved for IL in micropores and in nitrogen-doped carbon. This effect is so large that it is already seen in TGA and DSC experiments. Due to the low vapor pressure of the IL, standard volumetric sorption experiments can be used to quantify details of this effect. It is reasoned that it is the change of the molecular arrangement of the ions in the restricted space of the pores that creates additional free volume to host molecular nitrogen.}, language = {en} } @article{KirchheckerTroegerMuellerBakeetal.2015, author = {Kirchhecker, Sarah and Tr{\"o}ger-M{\"u}ller, Steffen and Bake, Sebastian and Antonietti, Markus and Taubert, Andreas and Esposito, Davido}, title = {Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions}, series = {Green chemistry}, volume = {8}, journal = {Green chemistry}, number = {17}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9262}, doi = {10.1039/c5gc00913h}, pages = {4151 -- 4156}, year = {2015}, abstract = {Fully renewable pyridinium ionic liquids were synthesised via the hydrothermal decarboxylation of pyridinium zwitterions derived from furfural and amino acids in flow. The functionality of the resulting ionic liquid (IL) can be tuned by choice of different amino acids as well as different natural carboxylic acids as the counterions. A representative member of this new class of ionic liquids was successfully used for the synthesis of ionogels and as a solvent for the Heck coupling.}, language = {en} } @article{KirchheckerTroegerMuellerBakeetal.2015, author = {Kirchhecker, Sarah and Tr{\"o}ger-M{\"u}ller, Steffen and Bake, Sebastian and Antonietti, Markus and Taubert, Andreas and Esposito, Davide}, title = {Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions}, series = {Green chemistry : an international journal and green chemistry resource}, volume = {17}, journal = {Green chemistry : an international journal and green chemistry resource}, number = {8}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9262}, doi = {10.1039/c5gc00913h}, pages = {4151 -- 4156}, year = {2015}, abstract = {Fully renewable pyridinium ionic liquids were synthesised via the hydrothermal decarboxylation of pyridinium zwitterions derived from furfural and amino acids in flow. The functionality of the resulting ionic liquid (IL) can be tuned by choice of different amino acids as well as different natural carboxylic acids as the counter-ions. A representative member of this new class of ionic liquids was successfully used for the synthesis of ionogels and as a solvent for the Heck coupling.}, language = {en} } @misc{KirchheckerTroegerMuellerBakeetal.2015, author = {Kirchhecker, Sarah and Tr{\"o}ger-M{\"u}ller, Steffen and Bake, Sebastian and Antonietti, Markus and Taubert, Andreas and Esposito, Davido}, title = {Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81390}, year = {2015}, abstract = {Fully renewable pyridinium ionic liquids were synthesised via the hydrothermal decarboxylation of pyridinium zwitterions derived from furfural and amino acids in flow. The functionality of the resulting ionic liquid (IL) can be tuned by choice of different amino acids as well as different natural carboxylic acids as the counterions. A representative member of this new class of ionic liquids was successfully used for the synthesis of ionogels and as a solvent for the Heck coupling.}, language = {en} } @misc{IlicTsoukaPerovicetal.2020, author = {Ilic, Ivan K. and Tsouka, Alexandra and Perovic, Milena and Hwang, Jinyeon and Heil, Tobias and L{\"o}ffler, Felix F. and Oschatz, Martin and Antonietti, Markus and Liedel, Clemens}, title = {Sustainable cathodes for Lithium-ion energy storage devices based on tannic acid-toward ecofriendly energy storage}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1}, issn = {1866-8372}, doi = {10.25932/publishup-57056}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-570560}, pages = {10}, year = {2020}, abstract = {The use of organic materials with reversible redox activity holds enormous potential for next-generation Li-ion energy storage devices. Yet, most candidates are not truly sustainable, i.e., not derived from renewable feedstock or made in benign reactions. Here an attempt is reported to resolve this issue by synthesizing an organic cathode material from tannic acid and microporous carbon derived from biomass. All constituents, including the redox-active material and conductive carbon additive, are made from renewable resources. Using a simple, sustainable fabrication method, a hybrid material is formed. The low cost and ecofriendly material shows outstanding performance with a capacity of 108 mAh g(-1) at 0.1 A g(-1) and low capacity fading, retaining approximately 80\% of the maximum capacity after 90 cycles. With approximately 3.4 V versus Li+/Li, the cells also feature one of the highest reversible redox potentials reported for biomolecular cathodes. Finally, the quinone-catecholate redox mechanism responsible for the high capacity of tannic acid is confirmed by electrochemical characterization of a model compound similar to tannic acid but without catecholic groups.}, language = {en} } @misc{AlNajiSchlaadAntonietti2020, author = {Al-Naji, Majd and Schlaad, Helmut and Antonietti, Markus}, title = {New (and old) monomers from biorefineries to make polymer chemistry more sustainable}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {3}, issn = {1866-8372}, doi = {10.25932/publishup-57061}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-570614}, pages = {13}, year = {2020}, abstract = {This opinion article describes recent approaches to use the "biorefinery" concept to lower the carbon footprint of typical mass polymers, by replacing parts of the fossil monomers with similar or even the same monomer made from regrowing dendritic biomass. Herein, the new and green catalytic synthetic routes are for lactic acid (LA), isosorbide (IS), 2,5-furandicarboxylic acid (FDCA), and p-xylene (pXL). Furthermore, the synthesis of two unconventional lignocellulosic biomass derivable monomers, i.e., alpha-methylene-gamma-valerolactone (MeGVL) and levoglucosenol (LG), are presented. All those have the potential to enter in a cost-effective way, also the mass market and thereby recover lost areas for polymer materials. The differences of catalytic unit operations of the biorefinery are also discussed and the challenges that must be addressed along the synthesis path of each monomers.}, language = {en} }