FG Funktionsmaterialien

38 Items

Recent Submissions
Multivalent Polyanionic 2D Nanosheets Functionalized Nanofibrous Stem Cell‐based Neural Scaffolds

Xia, Yi ; Yang, Hua ; Li, Shuang ; Zhou, Suqiong ; Wang, Liyun ; Tang, Yuanjiao ; Cheng, Chong ; Haag, Rainer (2021-03-10)

Because developed neural cells are no longer regenerative and proliferative, achieving neural regenerations by using induced pluripotent stem cells (IPS cells) for nerve diseases have recently attracted much attention. Since the IPS cells’ growth and differentiation can be manipulated by different physical and chemicals cues, scaffolds combining the beneficial nanostructures and extracellular m...

Designing MOF Nanoarchitectures for Electrochemical Water Splitting

Zhang, Ben ; Zheng, Yijuan ; Ma, Tian ; Yang, Chengdong ; Peng, Yifei ; Zhou, Zhihao ; Zhou, Mi ; Li, Shuang ; Wang, Yinghan ; Cheng, Chong (2021-03-22)

Electrochemical water splitting has attracted significant attention as a key pathway for the development of renewable energy systems. Fabricating efficient electrocatalysts for these processes is intensely desired to reduce their overpotentials and facilitate practical applications. Recently, metal–organic framework (MOF) nanoarchitectures featuring ultrahigh surface areas, tunable nanostructur...

Immobilization of an iridium pincer complex in a microporous polymer for application in room-temperature gas phase catalysis

König, Michaela ; Rigo, Massimo ; Chaoui, Nicolas ; Ngoc, Trung Tran ; Epping, Jan Dirk ; Schmidt, Johannes ; Pachfule, Pradip ; Ye, Meng-Yang ; Trunk, Matthias ; Teichert, Johannes F. ; Drieß, Matthias ; Thomas, Arne (2020-07-02)

An iridium dihydride pincer complex [IrH2(POCOP)] is immobilized in a hydroxy-functionalized microporous polymer network using the concepts of surface organometallic chemistry. The introduction of this novel, truly innocent support with remote OH-groups enables the formation of isolated active metal sites embedded in a chemically robust and highly inert environment. The catalyst maintained high...

A Ru-Complex Tethered to a N-Rich Covalent Triazine Framework for Tandem Aerobic Oxidation-Knoevenagel Condensation Reactions

Watson, Geert ; Gohari Derakhshandeh, Parviz ; Abednatanzi, Sara ; Schmidt, Johannes ; Leus, Karen ; Van Der Voort, Pascal (2021-02-05)

Herein, a highly N-rich covalent triazine framework (CTF) is applied as support for a RuIII complex. The bipyridine sites within the CTF provide excellent anchoring points for the [Ru(acac)2(CH3CN)2]PF6 complex. The obtained robust RuIII@bipy-CTF material was applied for the selective tandem aerobic oxidation-Knoevenagel condensation reaction. The presented system shows a high catalytic perform...

Ultralight covalent organic framework/graphene aerogels with hierarchical porosity

Li, Changxia ; Yang, Jin ; Pachfule, Pradip ; Li, Shuang ; Ye, Meng-Yang ; Schmidt, Johannes ; Thomas, Arne (2020-09-18)

The fabrication of macroscopic objects from covalent organic frameworks (COFs) is challenging but of great significance to fully exploit their chemical functionality and porosity. Herein, COF/reduced graphene oxide (rGO) aerogels synthesized by a hydrothermal approach are presented. The COFs grow in situ along the surface of the 2D graphene sheets, which are stacked in a 3D fashion, forming an ...

Donor–acceptor covalent organic frameworks for visible light induced free radical polymerization

Pachfule, Pradip ; Acharjya, Amitava ; Roeser, Jérôme ; Sivasankaran, Ramesh P. ; Ye, Meng-Yang ; Brückner, Angelika ; Schmidt, Johannes ; Thomas, Arne (2019-08-05)

Covalent organic frameworks (COFs) are promising materials for applications in photocatalysis, due to their conjugated, porous and chemically stable architectures. Alternating electron donor–acceptor-type structures are known to enhance charge carrier transport mobility and stability in polymers and are therefore also interesting building units for COFs used as photocatalysts but also as photoi...

Mechanistic studies of atomic layer deposition on oxidation catalysts – AlOx and POx deposition

Knemeyer, Kristian ; Hermida, Mar Piernavieja ; Ingale, Piyush ; Schmidt, Johannes ; Kröhnert, Jutta ; Naumann d’Alnoncourt, Raoul ; Driess, Matthias ; Rosowski, Frank (2020-07-15)

Atomic layer deposition is a rising technique for catalyst synthesis and modification. Typically, the focus of ALD in catalysis is on supported metal nanoparticles. Here, the authors give mechanistic insights into the ALD of oxides on redox active catalysts by a combination of in situ analytics, such as XPS, DRIFTS and gravimetric measurements. Phosphorus oxide and aluminum oxide were deposited...

Atomic Layer Deposition of ZnO on Mesoporous Silica: Insights into Growth Behavior of ZnO via In-Situ Thermogravimetric Analysis

Ingale, Piyush ; Knemeyer, Kristian ; Piernavieja Hermida, Mar ; Naumann d’Alnoncourt, Raoul ; Thomas, Arne ; Rosowski, Frank (2020-05-20)

ZnO is a remarkable material with many applications in electronics and catalysis. Atomic layer deposition (ALD) of ZnO on flat substrates is an industrially applied and well-known process. Various studies describe the growth of ZnO layers on flat substrates. However, the growth characteristics and reaction mechanisms of atomic layer deposition of ZnO on mesoporous powders have not been well stu...

Cobalt‐Exchanged Poly(Heptazine Imides) as Transition Metal–Nx Electrocatalysts for the Oxygen Evolution Reaction

Ye, Meng‐Yang ; Li, Shuang ; Zhao, Xiaojia ; Tarakina, Nadezda V. ; Teutloff, Christian ; Chow, Wing Ying ; Bittl, Robert ; Thomas, Arne (2020-01-27)

Poly(heptazine imides) hosting cobalt ions as countercations are presented as promising electrocatalysts for the oxygen evolution reaction (OER). A facile mixed‐salt melt‐assisted condensation is developed to prepare such cobalt poly(heptazine imides) (PHI‐Co). The Co ions can be introduced in well‐controlled amounts using this method, and are shown to be atomically dispersed within the imide‐l...

Colloid-based heterogeneous catalysts with tunable size and surface properties

Sagaltchik, Anton (2020)

Improvements in catalyst’s performance for technical processes stagnated over the last decades. The need for new approaches towards better performing catalysts is apparent. In this thesis, colloidal synthesis methods are examined for different heterogeneously catalyzed reactions. In chapter 2, synthesis of silver colloids with narrow particle size distributions for a particle size distribution...

Pd nanoparticles confined in mesoporous N-doped carbon silica supports: a synergistic effect between catalyst and support

Oliveira, Rafael L. ; Kerstien, Julius ; Schomäcker, Reinhard ; Thomas, Arne (2020-01-21)

Palladium nanoparticles of similar size were deposited on different supports, layers of carbon materials (with and without nitrogen doping) on the surface of a MCF (mesocellular foam) silica. For the generation of the N-doped carbon coatings, three different N sources were used to also investigate a possible influence of the N-doped carbon precursor and thus the structure of the N-doped carbons...

Vinylene-Linked Covalent Organic Frameworks by Base-Catalyzed Aldol Condensation

Acharjya, Amitava ; Pachfule, Pradip ; Roeser, Jérôme ; Schmitt, Franz-Josef ; Thomas, Arne (2019-09-09)

Two 2D covalent organic frameworks (COFs) linked by vinylene (−CH=CH−) groups (V‐COF‐1 and V‐COF‐2) are synthesized by exploiting the electron deficient nature of the aromatic s‐triazine unit of C3‐symmetric 2,4,6‐trimethyl‐s‐triazine (TMT). The acidic terminal methyl hydrogens of TMT can easily be abstracted by a base, resulting in a stabilized carbanion, which further undergoes aldol condensa...

Sythesis of functional nanoporous materials for electrocatalytic applications

Zhao, Xiaojia (2019)

Recently, the International Energy Agency has reported that the global energy demand is growing at the fastest pace this decade, while fossil fuels are leading the charge. The outcome of this is a higher carbon dioxide emission and environmental pollution, which can only be averted by developing all clean energy solutions and improving their efficiency. The development of electrocatalysis for r...

Optimisation of Surface-Initiated Photoiniferter-Mediated Polymerisation under Confinement, and the Formation of Block Copolymers in Mesoporous Films

Tom, Jessica ; Brilmayer, Robert ; Schmidt, Johannes ; Andrieu-Brunsen, Annette (2017-10-23)

Nature as the ultimate inspiration can direct, gate, and selectively transport species across channels to fulfil a specific targeted function. Harnessing such precision over local structure and functionality at the nanoscale is expected to lead to indispensable developments in synthetic channels for application in catalysis, filtration and sensing, and in drug delivery. By combining mesoporous ...

Relations between Structure, Activity and Stability in C3N4 Based Photocatalysts Used for Solar Hydrogen Production

Sivasankaran, Ramesh P. ; Rockstroh, Nils ; Hollmann, Dirk ; Kreyenschulte, Carsten R. ; Agostini, Giovanni ; Lund, Henrik ; Acharjya, Amitava ; Rabeah, Jabor ; Bentrup, Ursula ; Junge, Henrik ; Thomas, Arne ; Brückner, Angelika (2018-01-29)

Solar hydrogen production from water could be a sustainable and environmentally friendly alternative to fossil energy carriers, yet so far photocatalysts active and stable enough for large-scale applications are not available, calling for advanced research efforts. In this work, H2 evolution rates of up to 1968 and 5188 μmol h−1 g−1 were obtained from aqueous solutions of triethanolamine (TEOA)...

Structure–Thermodynamic‐Property Relationships in Cyanovinyl‐Based Microporous Polymer Networks for the Future Design of Advanced Carbon Capture Materials

Yassin, Ali ; Trunk, Matthias Georg ; Czerny, Frank ; Fayon, Pierre ; Trewin, Abbie ; Schmidt, Johannes ; Thomas, Arne (2017)

Nitrogen‐rich solid absorbents, which have been immensely tested for carbon dioxide capture, seem until this date to be without decisive molecular engineering or design rules. Here, a family of cyanovinylene‐based microporous polymers synthesized under metal‐catalyzed conditions is reported as a promising candidate for advanced carbon capture materials. These networks reveal that isosteric heat...

Room-Temperature Activation of Hydrogen by Semi-immobilized Frustrated Lewis Pairs in Microporous Polymer Networks

Trunk, Matthias Georg ; Teichert, Johannes F. ; Thomas, Arne (2017)

Porous polymer networks based on sterically encumbered triphenylphosphine motifs, mimicking the basic sites employed in frustrated Lewis pair (FLP) chemistry, were synthesized via Yamamoto polymerization and their interactions with the strong Lewis acid B(C6F5)3 probed. The combinations yield semi-immobilized FLPs, which are able to cleave dihydrogen heterolytically at ambient temperature and l...

Nanostructured porous carbon synthesized from metal-organic precursors as efficient electrochemical catalysts

Li, Shuang (2019)

The development of electrocatalysts for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) is of crucial importance to address the global demand for sustainable energy conversion devices with high efficiency, such as fuel cells and metal–air batteries, and the production of hydrogen by electrolysis of water. Nanostructured carbons are pro...

Copper‐Free Sonogashira Coupling for High‐Surface‐Area Conjugated Microporous Poly(aryleneethynylene) Networks

Trunk, Matthias Georg ; Herrmann, Anna ; Bildirir, Hakan ; Yassin, Ali ; Schmidt, Johannes ; Thomas, Arne (2016)

A modified one‐pot Sonogashira cross‐coupling reaction based on a copper‐free methodology has been applied for the synthesis of conjugated microporous poly(aryleneethynylene) networks (CMPs) from readily available iodoarylenes and 1,3,5‐triethynylbenzene. The polymerization reactions were carried out by using equimolar amounts of halogen and terminal alkyne moieties with extremely small loading...

Frustrated Lewis pairs embedded into microporous polymer networks

Trunk, Matthias Georg (2018)

Aufgrund ihrer vielseitigen potentiellen Anwendungsmöglichkeiten in Gasspeicherung und –trennung, Sensorik und Katalyse haben mikroporöse organische Materialien innerhalb der letzten 20 Jahre eine rasante Entwicklung erfahren. Neben geordneten Materialien wie metall-organischen Gerüstmaterialien (MOFs) und kovalent organischen Gerüstmaterialien (COFs) haben sich mikroporöse Polymernetzwerke (MP...