Nanoscience News (<front>)

Exclusive construction of graphitic nitrogen coordinated with pentagon defects is achieved by pyrolysis of zeolitic imidazolate framework-8 under unusually high temperatures. The graphitic nitrogen model electrocatalyst enables highly efficient four-electron oxygen reduction reaction in both alkaline and acidic conditions, as evidenced by in situ electrochemical Raman spectroscopy.

Abstract

Nitrogen-doped carbon materials have emerged as promising metal-free electrocatalysts for oxygen reduction reaction (ORR) in fuel cells and metal-air batteries. However, the structural inhomogeneity, particularly the coexistence of four nitrogen doping structures–pyridinic, graphitic, pyrrolic, and oxidized nitrogen–makes assessing their respective contributions challenging and controversial. The current understanding of the four nitrogen doping structures may be also oversimplified and even problematic. The development of a distinctive graphitic-N-doped carbon electrocatalyst is presented in which graphitic nitrogen coordinated with pentagon defects is selectively constructed. Contrary to the previously held belief that graphitic nitrogen has little effect on ORR electrocatalysis, the unique graphitic N configuration exhibited significantly enhanced four-electron ORR activity in both alkaline and acidic media. In situ electrochemical Raman spectroscopy combined with density functional theory calculations further revealed that graphitic nitrogen, when coordinated with pentagon defects, optimized the density of states near the Fermi level, leading to optimized binding energies with oxygen-containing intermediates. The results rationalize the long-standing controversy over the role of different nitrogen dopants in ORR electrocatalysis and suggest that there is considerable potential to precisely construct new nitrogen doping configurations to achieve superior electrocatalytic performance.

In situ polymerized polyfluorinated crosslinked polyether electrolytes are engineered for high-voltage Li metal batteries. Electron-withdrawing fluorinated groups enhance oxidative stability, improve interfacial compatibility, and promote inorganic-rich solid electrolyte interphase formation for uniform Li deposition. Ah-level Li||NCM811 pouch cells achieve 401.8 Wh kg−1 specific energy, showcasing promise for practical high-energy-density solid-state Li metal batteries.

Abstract

In situ polymerized polyether electrolytes are promising for solid-state Li metal batteries due to their high ionic conductivity and excellent interfacial contact. However, their practical application is hindered by Li dendrite formation, interfacial degradation, and limited oxidative stability. Herein, we propose an in situ polymerized polyfluorinated crosslinked polyether electrolyte (PDOL-OFHDBO), synthesized by copolymerizing 1,3-dioxolane (DOL) with 2,2′-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(oxirane) (OFHDBO) as a polyfluorinated crosslinker. The electron-withdrawing polyfluorinated groups endow PDOL-OFHDBO with enhanced oxidative stability and interfacial compatibility, while reducing the solvation power of the polymer matrix to promote an anion-derived inorganic-rich solid electrolyte interphase for uniform Li deposition. Consequently, PDOL-OFHDBO exhibits a wide electrochemical stability window (>5.6 V) and enables long-term stable Li plating/stripping for over 1100 h. Furthermore, Li||LiNi0.8Co0.1Mn0.1O2 (NCM811) full cells utilizing PDOL-OFHDBO demonstrate outstanding cycling stability with high-loading cathodes (≈3.8 mAh cm−2) and thin Li anodes (50 µm), achieving capacity retention of 95.5% and 89.1% over 100 cycles at cut-off voltages of 4.3 and 4.5 V, respectively. Remarkably, Ah-level Li||NCM811 pouch cells deliver an impressive specific energy of 401.8 Wh kg−1, highlighting their potential for practical solid-state Li metal batteries.

Practical high-temperature high-voltage thermal charging cells, incorporating heat-resistant Ca–Li salt, C4mimAOT-AmimCl co-solvent, and PEN@ZrBDC-F-4% separators, are successfully developed. These advancements are attributed to enhanced energy storage of dual carriers, improved diffusion kinetics facilitated by the AmimCl solvent and optimized carrier mobility enabled by the anionophilic properties of ZrBDC. The research holds significant promise for high-temperature, high-performance waste heat harvesting.

Abstract

Thermoelectric technologies (TEs) offer immense potential for waste heat recovery and energy storage. However, the practical application of current TEs has been severely hampered by potential performance degradation in extreme environments, particularly at high temperatures, due to electrolyte flammability or poor carrier mobility. The development of high-temperature, high-performance TEs is crucial for broadening their operational range and enabling diverse applications. Here, practical high-temperature high-voltage thermal charging cells (HHTCCs) are reported, facilitated by a heat-resistant trifluoromethanesulfonate-based Ca–Li dual-cationic ionic liquid electrolyte containing functionalized AmimCl solvent, together with a thermotolerant composite membrane, PEN(polyphenylene-ether-nitrile)@ZrBDC-F-4%. The dual-cation mechanism enables high thermal voltage through cooperative energy storage, while the functionalized AmimCl accelerates the mobility of Ca2+ and Li+ ions by weakening the surrounding shielding effect. Additionally, the anionophilic ZrBDC-F-4% nanoparticles in the composite membrane enhance carrier migration. As a result, the HHTCCs exhibit an impressive thermal voltage of 1.138 V, a remarkable thermopower of 15.3 mV K−1, and an outstanding Carnot-relative efficiency of 9.56% over an unprecedented temperature range from 328.15 to 393.15 K, demonstrating the excellent safety and feasibility of HHTCCs. This work expands the service-temperature range of i-TEs, holding significant promise for high-temperature, high-performance waste heat harvesting.

Unperceivable wearable technologies seamlessly integrate into everyone's daily life, for healthcare and Internet-of-Things applications. By remaining completely unnoticed both visually and tactilely, by the user and others, they ensure medical privacy and allow natural social interactions. Herein are introduced recent strategies employed at material, design, and integration levels to reach unperceivable technologies, whether through transparent materials or strategically hidden devices.

Abstract

Wearable smart electronics are taking an increasing part of the consumer electronics market, with applications in advanced healthcare systems, entertainment, and Internet of Things. The advanced development of flexible, stretchable, and breathable electronic materials has paved the way to comfortable and long-term wearables. However, these devices can affect the wearer's appearance and draw attention during use, which may impact the wearer's confidence and social interactions, making them difficult to wear on a daily basis. Apart from comfort, one key condition for user acceptance is that these new technologies seamlessly integrate into our daily lives, remaining unperceivable to others. In this review, strategies to minimize the visual impact of wearable devices and make them more suitable for daily use are discussed. These new devices focus on being unperceivable when worn and comfortable enough that users almost forget their presence, reducing psychological discomfort while maintaining accuracy in signal collection. Materials selection is crucial for developing long-term and unperceivable wearable devices. Recent developments in these unperceivable electronic devices are also covered, including sensors, transistors, and displays, and mechanisms to achieve unperceivability are discussed. Finally, the potential applications are summarized and the remaining challenges and prospects are discussed.

A non-contact Pt-ionomer microenvironment is strategically engineered to alleviate the sulfonate group-induced poisoning effect on Pt active sites by encapsulating Pt-based nanoalloys within porous nanofibers. This innovative architecture significantly enhanced proton exchange membrane fuel cell performance, achieving a remarkable peak power density of 29.0 kW gPt −1 and an exceptional initial mass activity of 0.69 A mgPt −1.

Abstract

Carbon-supported Pt-based catalysts in fuel cells often suffer from sulfonate poisoning, reducing Pt utilization and activity. Herein, a straightforward strategy is developed for synthesizing a porous PtCoV nanoalloy embedded within the porous structures of carbon nanofibers. Incorporation of vanadium (V) atoms into the PtCo alloy optimizes the oxygen binding energy of Pt sites, while heightening the dissolution energy barrier for both Pt and Co atoms, leading to a significantly enhanced intrinsic activity and durability of the catalyst. By encapsulating the nanoalloys within porous nanofibers, a non-contact Pt-ionomer interface is created to mitigate the poisoning effect of sulfonate groups to Pt sites, while promoting oxygen permeation and allowing proton transfer. This rational architecture liberates additional active Pt sites, while the evolved porous nanostructure of the PtCoV alloy extends its exposed surface area, thereby boosting Pt utilization within the catalytic layer and overall fuel cell performance. The optimized catalyst demonstrates an exceptional peak power density of 29.0 kW gPt −1 and an initial mass activity of 0.69 A mgPt −1, which exceeds the U.S. Department of Energy 2025 targets. This study provides a promising avenue for developing highly active and durable low-Pt electrocatalysts for fuel cell applications.

This work demonstrates that PTO/CCMO/SRO heterostructure can hold a broad family of skyrmion-like polar textures. One can write regular skyrmion bubble patterns with a high density ≈300 Gbit per inch2 by local tip field. The multiple π-twist target skyrmions and skyrmion bags show significant topology-enhanced stability, verifying a topology strategy to encode robust information in ferroelectrics.

Abstract

Topological textures like vortices, labyrinths, and skyrmions formed in ferroic materials have attracted extensive interest during the past decade for their fundamental physics, intriguing topology, and technological prospects. So far, polar skyrmions remain scarce in ferroelectrics as they require a delicate balance between various dipolar interactions. Here, it is reported that PbTiO3 thin films in a metallic contact undergo a topological phase transition and hold a broad family of skyrmion-like textures including Q = ±1 skyrmions, multiple π-twist target skyrmions, and skyrmion bags, with independent controllability, analogous to those reported in magnetic systems. Weakly-interacted skyrmion arrays with a density over 300 Gbit/inch2 are successfully written, erased, and read out by local electrical and mechanical stimuli of a scanning probe. Interestingly, in contrast to the relatively short lifetime (<20 hours) of the normal skyrmions, the multiple π-twist target skyrmions and skyrmion bags show topology-enhanced stability with a lifetime of over two weeks. Experimental and theoretical analysis implies the heterostructures carry electric Dzyaloshinskii–Moriya interaction mediated by oxygen octahedral tiltings. The results demonstrate ferroelectric-metallic heterostructures as fertile playgrounds for topological states and emergent phenomena.

Monolayers of transition-metal dichalcogenides exhibit strong exciton resonances for light-matter interactions at RT, though substrate effects limit performance. This work presents a planar microcavity with a suspended WS2 monolayer, eliminating substrate-induced losses. The system shows enhancement of strong coupling and preserves the spin-dependent polaritonic interactions, achieving a record exciton interaction constant close to theoretical predictions. This approach reveals the intrinsic optical and spintronic properties of 2D materials, paving the way for advanced polaritonic.

Abstract

Transition-metal dichalcogenides monolayers exhibit strong exciton resonances that enable intense light-matter interactions. The sensitivity of these materials to the surrounding environment and their interactions with the substrate result in the enhancement of excitonic losses through scattering, dissociation and defects formation, hindering their full potential for the excitation of optical nonlinearities in exciton-polariton platforms. The use of suspended monolayers holds the potential to completely eliminate substrate-induced losses, offering unique advantages for the exploitation of intrinsic electronic, mechanical, and optical properties of 2D materials-based polaritonic systems, without any influence of proximity effects. In this work, we report a novel fabrication approach enabling the realization of a planar microcavity filled with a suspended tungsten disulfide (WS2) monolayer in its center. We experimentally demonstrate a 2-fold enhancement of the strong coupling at room temperature, due to the larger exciton binding energy and reduced overall losses as compared to similar systems based on dielectric-filled microcavities. As a result, spin-dependent polaritonic interactions are significantly amplified, leading to achievement of a record exciton interaction constant approaching the theoretically predicted value. This approach holds promises for pushing 2D materials-based polaritonic systems to their intrinsic limits, paving the way for the realization of novel polaritonic devices with superior performance.

Title to be confirmed

Abstract not available

• Speaker: Lee McIntyre (Boston University)
• Wednesday 07 May 2025, 16:00-17:00
• Venue: Ground Floor Lecture Theatre, Department of Psychology, Downing Site, Cambridge.
• Series: Social Psychology Seminar Series (SPSS); organiser: Yara Kyrychenko.

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CO2 Hydration at the Air-Water Interface: A Surface-Mediated ‘In and Out’ Mechanism

An understanding of the CO2 + H2O hydration reaction is crucial for modeling the effects of ocean acidification, for enabling novel carbon storage solutions, and as a model process in the geosciences. While the mechanism of this reaction has been investigated extensively in the condensed phase, its mechanism at the air-water interface remains elusive, leaving uncertain the contribution that surface-adsorbed CO2 makes to the overall acidification reaction. In this study, we employ state-of-the-art machine-learned potentials to provide a molecular-level understanding of CO2 hydration at the air-water interface. We show that reaction at the interface follows a surface-mediated ‘In and Out’ mechanism: CO2 diffuses into the aqueous surface layer, reacts to form carbonic acid, and is subsequently expelled from solution. We show that this surface layer provides a bulk-like solvation environment, engendering similar modes of reactivity and near-identical free energy profiles for the bulk and interfacial processes. Our study unveils a new, unconventional reaction mechanism that underscores the dynamic nature of the molecular reaction site at the air-water interface. The similarity between bulk and interfacial profiles shows that CO2 hydration is equally as feasible under these two solvation environments and that acidification rates are likely enhanced by this additional surface contribution.

• Speaker: Samuel Brookes, University of Cambridge
• Wednesday 21 May 2025, 14:30-15:00
• Venue: Unilever Lecture Theatre, Yusuf Hamied Department of Chemistry.
• Series: Theory - Chemistry Research Interest Group; organiser: Lisa Masters.

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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D4EE04526B, Review Article Open Access &nbsp This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.Vijay C Karade, Mingrui He, Abasi Abudulimu, Zhaoning Song, Yeonwoo Park, Donghoon Song, Yanfa Yan, Jin Hyeok Kim, Randy Ellingson, Jae Ho Yun, Xiaojing Hao, Seung Wook Shin, Mahesh P. Suryawanshi
This review highlights the promise of emerging inorganic chalcogenide-silicon (Si) tandem solar cells (TSCs) to overcome the power conversion efficiency (PCE) and long-term stability limitations of single-junction solar cells, advancing...
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Nature Materials, Published online: 02 May 2025; doi:10.1038/s41563-025-02186-x

By studying Eshelby twisted GeS nanowires with a single central dislocation, an anomalous dependence of thermal conductivity on nanowire diameter is observed, caused by compressive strain improving thermal transport.

Nature Materials, Published online: 02 May 2025; doi:10.1038/s41563-025-02243-5

One-dimensional magnetism gets the attention it deserves.

Nature Materials, Published online: 02 May 2025; doi:10.1038/s41563-025-02187-w

Signatures of O2 molecules found in oxide-based battery electrodes through resonant inelastic X-ray scattering are now believed to be the extrinsic product of the intrinsic oxidized anions.

Nature Materials, Published online: 02 May 2025; doi:10.1038/s41563-025-02231-9

Graphene in proximity with pentagonal PdSe2 exhibits anisotropic and gate-tunable spin–orbit coupling, enabling a tenfold modulation of spin lifetime at room temperature.

Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D5EE00845J, PaperYuandong Sun, Liang Wang, Dawei Gao, Chen Chen, Zirui Gan, Jingchao Cheng, Jing Zhou, Dan Liu, Wei Li, Tao Wang
Extending the π-conjugated framework of Non-fullerene electron acceptors (NFAs) have been considered as an effective method to improve the optoelectronic properties, however, how does the conjugation extension affect the molecular...
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Reconstructing wintertime seawater pCO2 on the data-barren shelf of the western Weddell Sea based on summertime bottom water measurements

The dense waters formed on the broad shelf of the western Weddell Sea are a source of Weddell Sea Bottom Water (WSBW), which transports anthropogenic CO2 along the continental slope to the bottom of the ocean. Our updated time series shows a positive trend of carbon in WSBW . To understand the drivers for this pathway for carbon sequestration, we need to understand the processes affecting carbon concentrations in shelf waters at the time of dense water formation, which is predominantly during sea ice formation in winter. Unfortunately, wintertime marine observations are particularly scarce in the western Weddell Sea. We are therefore testing a method that reconstructs the seawater partial pressure of CO2 (pCO2) representative of wintertime conditions in this dense-water formation region, using carbonate chemistry observations made in WSBW in the summer. Results suggest that atmospheric CO2 uptake is the main driver of increasing carbon in WSBW , and thus that equilibration of surface seawater with the atmosphere is possible despite year-round sea ice cover in this region.

• Speaker: Elise Droste (University of East Anglia)
• Wednesday 07 May 2025, 14:00-15:00
• Venue: BAS Seminar Room 1.
• Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.

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Sums along binary cubic forms.

We discuss ongoing work with Joseph Leung in which we obtain estimates for sums of Fourier coefficients of GL(2) and certain GL(3) automorphic forms along the values of irreducible binary cubics.

• Speaker: Mayank Pandey (Princeton)
• Tuesday 06 May 2025, 14:30-15:30
• Venue: MR13.
• Series: Number Theory Seminar; organiser: Jef Laga.

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Title to be confirmed

Abstract not available

• Speaker: Emad Heydari Beni & Lode Hoste, Nokia Bell Labs
• Tuesday 27 May 2025, 14:00-15:00
• Venue: Webinar & LT2, Computer Laboratory, William Gates Building..
• Series: Computer Laboratory Security Seminar; organiser: Anna Talas.

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Abstract not available

• Speaker: Michael A. Specter, Georgia Tech
• Tuesday 17 June 2025, 14:00-15:00
• Venue: Webinar & LT2, Computer Laboratory, William Gates Building..
• Series: Computer Laboratory Security Seminar; organiser: Anna Talas.

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Title to be confirmed

Abstract not available

• Speaker: Michael A. Specter, Georgia Tech
• Thursday 01 May 2025, 14:00-15:00
• Venue: Webinar & LT2, Computer Laboratory, William Gates Building..
• Series: Computer Laboratory Security Seminar; organiser: Anna Talas.

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