Category Archives: Publications

One-pot Synthesis of High-capacity Sulfur Cathodes via In-situ Polymerization of a Porous Imine-based Polymer

Li,* G.; Liu, Y.; Schultz, T.; Exner, M.; Muydinov, R.; Wang, H.; Scheurell, K.; Huang, J.; Szymoniak, P.; Pinna, N.; Koch, N.; Adelhelm, P.; Bojdys,* M. J. Angew. Chem. Int. Ed. 2024. DOI: 10.1002/anie.202400382 [OPEN ACCESS]

Innovative research has brought us closer to sustainable battery technology with a breakthrough in sulfur-based cathodes. Traditionally, lithium-ion batteries—central to electronics and electric vehicles—rely on scarce materials like cobalt. Sulfur offers a greener alternative due to its abundance and impressive theoretical capacity of 1675 mAh g-1.

A major challenge with sulfur has been the “sulfur-shuttle” effect, where sulfur’s mobility leads to rapid battery degradation. However, a recent study introduces a novel solution: encapsulating sulfur within a microporous, imine-based polymer network directly on the current collector. This one-pot synthesis approach not only streamlines production but also significantly boosts battery performance.

This innovative cathode design enables selective electrolyte and Li-ion transport while robustly containing the sulfur, delivering high performance across discharge rates—from 1360 mAh g-1 at 0.1 C to 807 mAh g-1 at 3 C. Advanced analysis through DFT calculations and operando Raman spectroscopy has shown that the polymer’s imine groups enhance polysulfide binding, effectively reducing degradation.

This breakthrough paves the way for sulfur-based cathodes to become a viable alternative to metal-based ones, marking a significant step toward greener, high-performance battery technologies. Keep an eye on this space—sulfur could be the future of batteries!

[Press-release] ICSMB “Revolutionary development in the field of battery technology through innovative sulphur cathodes”

DOI: 10.1002/anie.202400382

Molecular Mobility and Gas Transport Properties of Mixed Matrix Membranes Based on PIM‑1 and a Phosphinine Containing Covalent Organic Framework

Emamverdi, F.; Huang, J.; Razavi, N. M.; Bojdys, M. J.; Foster, A. B.; Budd, P. M.; Schönhals, A. Macromolecules 2024. DOI: 10.1021/acs.macromol.3c02419

Researchers have developed a groundbreaking membrane technology by incorporating a novel covalent organic framework (COF), CPSF-EtO, into polymers with intrinsic microporosity (PIM-1), enhancing gas separation efficiency and membrane longevity. This innovative approach led to a significant 50% increase in carbon dioxide permeability and a 27% improvement in CO2/N2 selectivity, crucial for applications in carbon capture and natural gas purification. The addition of CPSF-EtO not only facilitates gas transport by creating additional free volume within the membrane but also counteracts the physical aging that typically diminishes membrane performance over time.

This advancement in membrane technology marks a significant leap forward, offering a more sustainable and cost-effective solution for gas separation processes, with promising implications for environmental protection and resource utilization.

Structure and molecular mobility of phosphinine-based covalent organic frameworks – glass transition of amorphous COFs

Emamverdi, F.; Huang, J.; Szymoniak, P.; Bojdys, M. J.; Böhning, M.; Schönhals, A. Mater. Adv. 2024. DOI: 10.1039/d3ma01123b

Scientists have identified a glass transition in amorphous covalent organic frameworks (COFs), a finding that challenges the conventional understanding of these materials. The research focused on two novel phosphinine-based COFs, distinguished by methoxy (CPSF-MeO) and ethoxy (CPSF-EtO) groups, revealing significant differences in their thermal behavior and structure.

The analysis demonstrated that CPSF-EtO transitions into a glass state at a temperature approximately 100 K higher than CPSF-MeO, attributed to the different ways in which the molecular layers stack and interact. This behavior was confirmed through both calorimetry and dielectric measurements, suggesting that these amorphous COFs exhibit glass-like properties.

This breakthrough opens up new possibilities for the application of COFs in various technologies, including gas storage and separation, by harnessing their unique structural and thermal characteristics.

Publishing and AI – On the decline of academic dime novels

Bojdys, M. J. Nachrichten aus der Chemie, Jul 2023, S. 10-14 DOI: 10.1002/nadc.20234137105 [GDCh App Link]

Farewell to Static Print and PDF Articles? ChemistryViews, Aug 2023 [Link]

At a glance

  • Individual parts of scientific publications, such as introductions, always follow the same narrative pattern. Therefore, AI tools can write such texts.
  • Already today, scientists publish more than can be read. With AI, there could be even more papers.
  • Therefore, the publication practice in science as it is today seems outdated and not a criterion for scientific quality.
  • Updatable FAIR data sets should form the backbone of scientific work in the future, instead of repetitive narratives and static prints and PDFs.

How text-generating artificial intelligence will challenge narrative scientific publishing.

Continue reading Publishing and AI – On the decline of academic dime novels

On the non-bonding valence band and the electronic properties of poly(triazine imide), a graphitic carbon nitride

Burmeister,* D.; Eljarrat, A.; Guerrini, M.; Röck, E.; Plaickner, J.; Koch, Ch. T.; Banerji, N.; Cocchi, C.; List-Kratochvil, E. J. W.; Bojdys,* M. J. Chem. Sci. 2023. DOI: 10.1039/D3SC00667K

PTI nano-crystals have quenched electroluminescence. Disorder at crystal interfaces limits charge transport in PTI films. For future device applications, single crystal devices using electron transport in the lowest conduction band show promise.

Interestingly, this is one of the first (?) publications in the chemical sciences that was openly co-authored by OpenAI’s GPT-3 that we used for the generation of the introduction section (see Acknowledgements). When generating an “Aristotelian narrative” (introduction, crisis, outlook), GPT was incredibly fast and effective.

We hope that this publication will contribute to a long-overdue discussion in academic publishing on whether the the static and “dead” publication in form of a PDF (especially as a summative review article) still is relevant and appropriate. In short: do we still need narrative publications, or should we aim for “Impact, not impact factor”.

One-pot synthesis of high-capacity silicon anodes via on-copper growth of a semiconducting, porous polymer

Huang, J.; Martin, A.; Urbanski, A.; Kulkarni, R.; Amsalem, P.; Exner, M.; Li, G.; Müller, J.; Burmeister, D.; Koch, N.; Brezesinski, T.; Pinna, N.; Uhlmann, P.; Bojdys,* M. J. Nat. Sci. 2022. DOI: 10.1002/ntls.20210105 & ChemRxiv 2022. DOI: 10.26434/chemrxiv-2021-jmrvw-v3

[Press-release] IDW-online “Neue Produktionsmethode für flexible, langlebige Anoden mit hoher Kapazität im Verhältnis zum Gewicht”

Key Points

  • We present a Si-based anode with superior-performance close to the limits of theoretical capacities with an advantage of factor ×10 over any hitherto produced, commercial electrode system.
  • Our electrodes sustain physical bending without surface reconstruction or crack formation, and heat shocks without loss of capacity and overall cycling performance.
  • The critical, novelty that enables the extraordinary performance increase and durability of our anodes is a class of semi-conducting porous organic polymers that replaces all conventional additives in battery ink formulations.

Size Effects of the Anions in the Ionothermal Synthesis of Carbon Nitride Materials

Burmeister, D.; Müller, J.; Plaickner, J.; Kochovski, Z.; List-Kratochvil, E. J. W.; Bojdys,* M. J. Chem. Eur. J. 2022. DOI: 10.1002/chem.202200705; Zenodo 2022. DOI: 10.5281/zenodo.6244965

Ionothermal condensation of dicyandiamide in alkali halide salt melts leads to the formation of extended 2D, layered frameworks only in the presence of small halides such as chloride, and bromide. With increasing size of the alkali halide intercalate, stabilizing van der Waals interactions between extended, π-conjugated triazine-based sheets are lost. We identify the main, crystalline product from an alkali iodide eutectic as melem hydrate, a heptazine (C6N7)-based, hydrogen-bonded, monoclinic solid.

Optimized synthesis of solution-processable crystalline poly(triazine imide) with minimized defects for OLED application

Burmeister, D.; Tran, H. A.; Müller, J.; Guerrini, M.; Cocchi, C.; Plaickner J.; Kochovski, Z.: List-Kratochvil, E.; Bojdys,* M. J. Angew. Chem. Int. Ed. 2021. DOI: 10.1002/anie.202111749 [OPEN ACCESS]

Crystalline semiconducting carbon nitrides are chemically and physically resilient, consist of earth abundant elements, and can be exfoliated into 2D atomically thin layers. In particular, poly(triazine imide) (PTI) is a highly crystalline semiconductor, and though no techniques exist to date that enable synthesis of macroscopic monolayers of PTI, it is possible to study it in thin layer device applications that are compatible with its polycrystalline, nanoscale morphology. In our study, we find that the by-product of conventional PTI synthesis is a C-C carbon rich phase that is detrimental for charge transport and photoluminescence. An optimised synthetic protocol yields a PTI material with an increased quantum yield, enabled photocurrent and electroluminescence. In addition, we report that protonation of the PTI structure happens preferentially at the pyridinic nitrogen atoms of the triazine (C3N3) rings, is accompanied by exfoliation of PTI layers, and contributes to increases in quantum yield and exciton lifetimes. This study describes structure-property relationships in PTI that link (i) the nature of defects, their formation, and how to avoid them with (ii) the optical and electronic performance of PTI. On the basis of our findings, we create an OLED prototype with PTI as the active, metal-free material, and we lay the foundations for device integration of solution-processable graphitic carbon nitride dispersions in semiconductor devices.

Press-releases: [IRIS, EN], [IRIS, DE], [KCL, EN], [HU, DE]

DOI: 10.1002/anie.202111749

Direct growth of crystalline triazine-based graphdiyne using surface-assisted deprotection-polymerisation

Kulkarni, R.; Huang, J.; Trunk, M.; Burmeister, D.; Amsalem, P.; Müller, J.; Martin, A.; Koch, N.; Kass, D.; Bojdys,* M. J. Chem. Sci. 2021. DOI: 10.1039/D1SC03390E [OPEN ACCESS]

Graphdiyne polymers have interesting electronic properties due to their π-conjugated structure and modular composition. Most of the known synthetic pathways for graphdiyne polymers yield amorphous solids because the irreversible formation of carbon-carbon bonds proceeds under kinetic control and because of defects introduced by the inherent chemical lability of terminal alkyne bonds in the monomers. Here, we present a one-pot surface-assisted deprotection/polymerisation protocol for the synthesis of crystalline graphdiynes over a copper surface starting with stable trimethylsilylated alkyne monomers. In comparison to conventional polymerisation protocols, our method yields large-area crystalline thin graphdiyne films and, at the same time, minimises detrimental effects on the monomers like oxidation or cyclotrimerisation side reactions typically associated with terminal alkynes. A detailed study of the reaction mechanism reveals that the deprotection and polymerisation of the monomer is promoted by Cu(II) oxide/hydroxide species on the as-received copper surface. These findings pave the way for the scalable synthesis of crystalline graphdiyne-based materials as cohesive thin films.

DOI: 10.1039/D1SC03390E