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F-N-C catalysts with high density of accessible sites (D-Fe-N/C) is fabricated by a cascade capturing strategy. Systematic structural and electrochemical characterizations demonstrate that the high active site density and site utilization enable D-Fe-N/C showcases excellent ORR performance, which is further verified in laminated zinc-air batteries with remarkable durability and temperature-adaptive.

Abstract

Designing single-atom catalysts (SACs) with high density of accessible sites by improving metal loading and sites utilization is a promising strategy to boost the catalytic activity, but remains challenging. Herein, a high site density (SD) iron SAC (D-Fe-N/C) with 11.8 wt.% Fe-loading is reported. The in situ scanning electrochemical microscopy technique attests that the accessible active SD and site utilization of D-Fe-N/C reach as high as 1.01 × 1021 site g−1 and 79.8%, respectively. Therefore, D-Fe-N/C demonstrates superior oxygen reduction reaction (ORR) activity in terms of a half-wave potential of 0.918 V and turnover frequency of 0.41 e site−1 s−1. The excellent ORR property of D-Fe-N/C is also demonstrated in the liquid zinc-air batteries (ZABs), which exhibit a high peak power density of 306.1 mW cm−2 and an ultra-long cycling stability over 1200 h. Moreover, solid-state laminated ZABs prepared by presetting an air flow layer show a high specific capacity of 818.8 mA h g−1, an excellent cycling stability of 520 h, and a wide temperature-adaptive from −40 to 60 °C. This work not only offers possibilities by improving metal-loading and catalytic site utilization for exploring efficient SACs, but also provides strategies for device structure design toward advanced ZABs.

The electrocatalytic reduction of nitrate into value-added NH3 not only facilitates wastewater denitrification but also promotes nitrogen circulation. The hierarchical carbon-based metal-free electrocatalyst with multi-topological defect-induced active sites in graphene sheets/outside carbon layer and the pristine carbon nanotubes as the conductive core achieves high activity and durability for electrocatalytic reduction of nitrate in a wide pH range.

Abstract

The electrocatalytic reduction of nitrate (eNO3 −RR) to ammonia (NH3) across varying pH is of great significance for the treatment of practical wastewater containing nitrate. However, developing highly active and stable catalysts that function effectively in a wide pH range remains a formidable challenge. Herein, a hierarchical carbon-based metal-free electrocatalyst (C-MFEC) of winged carbon coaxial nanocables (W-CCNs, in situ generated graphene nanosheets and outside carbon layer with abundant topological defects from pristine carbon nanotubes, CNTs), is prepared through moderate oxidation of CNTs and the subsequent introduction of topological defects. The W-CCNs feature functional separation properties, with an inner core of pristine CNTs that facilitates efficient charge transfer, while the outer shell is composed of in situ generated graphene nanosheets and carbon layers enriched with topological defects characterized by distinct carbon atom configurations, which play a crucial role in promoting the adsorption of NO3 −, the dissociation of water, and the N─H bond formation. This innovative design enables the C-MFEC to exhibit outstanding performance for eNO3 −RR, operating efficiently with the NH3 yield rates of 49.5, 75.3, and 88.1 g h−1 gcat. −1 in acidic, neutral, and alkaline media, respectively. Such performance metrics not only outshine C-MFECs but also rival or surpass those of certain metal-based catalysts.

Narrowband response of organic semiconductors determines the band selectivity and anti-interference in the photodetection process. For constructing strong anti-interference photodetectors, a general strategy is developed to achieve narrowband ultraviolet-responsive organic semiconductors by tuning the absorption state and intermolecular potential of organic semiconductor.

Abstract

Narrowband response of organic semiconductors determines the band selectivity and anti-interference of the organic photodetectors, which are pursued for a long time but have not yet been resolved in the UV band. Herein, a feasible strategy is developed to realize narrowband UV response by tuning the absorption state and intermolecular potential of organic semiconductors. The as-designed non-Donor-Acceptor molecule, 2,5-diphenylthieno[3,2-b]thiophene (2,5-DPTT), exhibits narrowband absorption by fully suppressing the charge transfer state absorption. Simultaneously, the intermolecular potential is significantly enhanced (to ≈90 KJ mol−1) by modulating the molecular planarity. Consequently, the UV photodetector based on 2,5-DPTT achieves excellent narrowband response at 310 nm wavelength and a record-breaking photosensitivity (P = 1.21 × 106) in the deep UV range. In the demonstration application of flame alarm, the flame detector based on 2,5-DPTT single crystal exhibits excellent anti-interference capability. This work provides the inspiration for designing narrowband responsive organic semiconductors and building up multifunctional optoelectronic devices.

A reliable benchmark for qualitative and quantitative analysis of oxygen functional groups on carbon surface is established by in situ characterizations and theoretical calculations. And the dynamic evolution of carbon surface reveals the special flame-retardant effect and anchor metal ability of oxygen functionalities on carbon materials. These findings strengthen the understanding of carbon surface chemistry from an atomic perspective.

Abstract

The explicit roles of the hardly avoidable oxygen species on carbon materials in various fields remain contentious due to the limitations of characterization techniques, which lead to a lack of fundamental understanding of carbon surface chemistry. This study delves exhaustively into the comprehension of the features of different oxygen-modified carbons through the dynamic evolution of surficial oxygen functional groups. Significant differences of thermal stability and electronic properties among various oxygen species are elucidated via in situ characterizations and theoretical calculations, providing a reliable benchmark for identifying oxygen functional groups on carbon materials. The chemical properties of the carbon materials are simultaneously investigated to show the influence of the oxygen functional groups on carbon structures, redox stability, and scalable metal adsorption. These findings not only consider the common misconception that oxygen species produced under various conditions possess identical properties but also raise awareness of understanding carbon surface chemistry in the atomic level.

A novel organic electrochemical device achieving over 90% reversible THz modulation via a conducting polymer is developed. The device demonstrates stability under repeated and continuous voltage switching and can operate in either depletion or accumulation modes. This device introduces a new option for future THz wireless sensing and communications, and application scope for organic mixed ionic-electronic conductors.

Abstract

The sub-Terahertz and Terahertz bands play a critical role in next-generation wireless communication and sensing technologies, thanks to the large amount of available bandwidth in this spectral regime. While long-wavelength (microwave to mm-Wave) and short-wavelength (near-infrared to ultraviolet) devices are well-established and studied, the sub-THz to THz regime remains relatively underexplored and underutilized. Traditional approaches used in the aforementioned spectral regions are more difficult to replicate in the THz band, leading to the need for the development of novel devices and structures that can manipulate THz radiation effectively. Herein a novel organic, solid-state electrochemical device is presented, capable of achieving modulation depths of over 90% from ≈500 nm of a conducting polymer that switches conductivity over a large dynamic range upon application of an electronically controllable external bias. The stability of such devices under long-term, repeated voltage switching, as well as continuous biasing at a single voltage, is also explored. Switching stabilities and long-term bias stabilities are achieved over two days for both use cases. Additionally, both depletion mode (always “ON”) and accumulation mode (always “OFF”) operation are demonstrated. These results suggest applications of organic electrochemical THz modulators in large area and flexible implementations.

Nature Materials, Published online: 07 February 2025; doi:10.1038/s41563-024-02112-7

Sublattice amorphization is revealed as the deformation mechanism of Ag2Te1–xSx (0.3 ≤ x ≤ 0.6), based on which an iterative crystalline–amorphous transition strategy is proposed to enable these bulk inorganic semiconductors with metal-like processability.

Nature Materials, Published online: 07 February 2025; doi:10.1038/s41563-024-02109-2

Pentagonal PdSe2 induces anisotropic, gate-tunable spin–orbit coupling in graphene, enabling a tenfold modulation of in-plane spin lifetimes at room temperature and providing opportunities to control spin dynamics in van der Waals materials.

Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D4EE04063E, Review ArticleWenhao Xu, Libo Li, Yangmingyue Zhao, Suo Li, Hang Yang, Hao Tong, Zhixuan Wang
In the pursuit of sustainable energy, lithium-ion batteries (LIBs) have revolutionized storage solutions and advanced the development of electric vehicles. However, as LIBs near their energy density limits and face...
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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D4EE03461A, PaperZhenye Li, Jiefeng Xie, Wenquan Wang, Zhiyuan Yang, Lixuan Kan, Zaiyu Wang, Ming Zhang, Wenyu Yang, Feng Peng, Wenkai Zhong, Ying Lei
Achieving high-performance organic photovoltaics (OPVs) hinges on optimizing the phase separation and interfaces within the active layer, which is crucial for efficient charge generation and transport. While a fibril-like phase-separated...
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A model-theoretic approach to Roth's theorem

The ultraproduct construction is a useful tool in model theory to study the asymptotic behavior of a class of structures. In the particular case of a class of finite groups, the ultralimit of the normalized counting measure yields a translation-invariant Keisler measure on internal sets, which has played a crucial role in the recent years in several applications of model-theoretic techniques to additive combinatorics.

In this talk, we present a model-theoretic result that resonates with Croot-Sisask’s almost periodicity technique for a general group equipped with a Keisler measure under some mild assumptions. We then show how to use this result to obtain, via an ultrafilter construction, a non-quantitative proof of Roth’s theorem on arithmetic progressions of length three. The core idea of our model-theoretic version of almost periodicity is the stability-like behaviour of a convolution of sets. We will not assume prior knowledge of model theory for this talk.

In the first part of the talk, aimed at a general (non-logic) audience, we will recall the ultraproduct construction of finite groups, as well as Łoś’s theorem, dense internal subsets and the main features of stable relations, in order to briefly outline how to prove a non-quantitative version of Roth’s theorem.

The second part of the talk will focus on a more detailed explanation of some aspects of the proofs, in particular the notions of dense and random elements and their features. If time permits, we will explain how some of these techniques can be adapted to study the collection of starting points of arithmetic progressions in the primes and in the square-free integers.

• Speaker: Amador Martin-Pizarro (Albert-Ludwigs-Universität Freiburg)
• Wednesday 12 February 2025, 13:30-15:00
• Venue: MR4, CMS.
• Series: Discrete Analysis Seminar; organiser: Julia Wolf.

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Insights into the Genetic Architecture of Neurodevelopmental Conditions and Traits from Large Cohorts

Abstract: Over the last fifteen years, high-throughput DNA sequencing of large patient cohorts has revolutionised the diagnosis and understanding of rare diseases, particularly rare neurodevelopmental conditions involving intellectual disability. Recent work in population-based cohorts such as UK Biobank has shown us that, contrary to earlier assumptions, the genetics of rare neurodevelopmental conditions overlaps with the genetics of cognitive ability, psychiatric disease and related traits in the general population. I will first discuss what we have learnt about the genetic architecture of neurodevelopmental conditions from the Deciphering Developmental Disorders study comprising over 13,000 patients. I will then present recent work on the common and rare genetic contributions to cognitive development from longitudinally-phenotyped birth cohorts and explain how this helps us make sense of observations from clinical studies.

The host for this talk is Varun Warrier

• Speaker: Dr. Hilary Martin, Wellcome Sanger Institute, Cambridge. UK
• Friday 28 February 2025, 12:00-13:30
• Venue: Ground Floor Lecture Theatre, Department of Psychology.
• Series: Zangwill Club; organiser: Sara Seddon.

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The Role of piracy in quantum proofs

Abstract not available

• Speaker: Alex Grilo (Sorbonne Université)
• Monday 10 March 2025, 14:00-15:00
• Venue: Computer Laboratory, William Gates Building, Room SS03.
• Series: Quantum Computing Seminar; organiser: Tom Gur.

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Walter Kohn: the theoretical physicist who created DFT and won the Nobel Prize for Chemistry

Abstract not available

• Speaker: Prof. Sir David Clary, FRS (University of Oxford)
• Thursday 22 May 2025, 14:00-15:30
• Venue: TCM Seminar Room.
• Series: Theory of Condensed Matter; organiser: Bo Peng.

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The Role of piracy in quantum proofs

Abstract not available

• Speaker: Alex Grilo (Sorbonne Université)
• Monday 10 March 2025, 14:00-15:00
• Venue: Computer Laboratory, William Gates Building, Room FW26.
• Series: Quantum Computing Seminar; organiser: Tom Gur.

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Quantum phases of matter under non-unitary dynamics

Recent breakthroughs in the development of digital quantum devices promise to grant computational capacities far beyond the reach of classical architectures, and open unprecedented possibilities to study quantum many-body systems. This swift progress is fueling intense interest in the complex interplay of unitary quantum dynamics and non-unitary processes arising naturally in experiments, such as dissipation stemming from coupling to the environment or projective measurements performed on the system. This talk illustrates the rich dynamical phase diagrams that can emerge in these non-unitary settings. In the first part, we address the challenges of protecting quantum coherence against environmental noise, and explore the dynamical phase diagram of dissipative quantum many-body systems. In contrast to the general expectation that in an open system coherent information is quickly lost to the dissipative environment, we construct a regime of open quantum dynamics, functioning as a quantum error-correcting code which is dynamically protected against generic boundary noise. We comment on the implications of these results for designing robust quantum devices. We then turn to the effects of local measurements performed on the system. Specifically, we demonstrate that appropriately chosen projective measurements can imprint highly non-trivial order on quantum many-body systems, realizing the out-of-equilibrium counterpart of spontaneous symmetry breaking and symmetry protected topological order.

• Speaker: Izabella Lovas, ETH Zurich
• Thursday 13 February 2025, 14:00-15:00
• Venue: TCM Seminar Room.
• Series: Theory of Condensed Matter; organiser: Gaurav.

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Neural circuit reorganisation and functional resilience

Most patients with functional impairments following brain damage show some degree of recovery over time—a pattern observed across language, motor, and visual domains. Yet, recovery remains highly variable and depends on lesion characteristics. What principles govern this variability? In this talk, I will present a computational approach to understanding how neural circuits reorganise to compensate for damage. Using generative models that mirror neural architectures, we can simulate specific lesion patterns and predict their functional outcomes. I will focus on speech processing, where our work demonstrates how precision-weighting between primary and alternative neural circuits shapes recovery trajectories, enabling paradoxical recovery through circuit rebalancing. I will then show how these insights align with our neuroimaging experiment, revealing that neural circuits flexibly engage different pathways even for basic cognitive operations like speech processing. Building on these findings, I will discuss our recent efforts to develop domain-general models of perceptual function. For this, we have formalised how information can be mapped across sensory modalities using optimal transport theory. This approach provides a quantitative framework to study cross-modal plasticity and the emergence of compensatory mechanisms through neural circuit interactions. Ultimately, this lays the groundwork for understanding brain-wide damage and functional resilience, and generating testable predictions that can guide future neuroimaging studies and therapeutic approaches.

• Speaker: Noor Sajid, Max Planck for Biological Cybernetics
• Tuesday 11 February 2025, 15:45-16:30
• Venue: CBL Seminar Room, Engineering Department, 4th floor Baker building.
• Series: Computational Neuroscience; organiser: Daniel Kornai.

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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D4EE05595K, Review Article Open Access &nbsp This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.Pingshan Jia, Junpo Guo, Qing Li, Yinan Liu, Yun Zheng, Yan Guo, Yike Huang, Yingying Shen, Lifen Long, Hebin Zhang, Rong Chen, Congcong Zhang, Zhiyuan Zhang, Jingjun Shen, Shengyang Dong, Jiangmin Jiang, Meinan Chang, Xupo Liu, Xiaobing Wang, Yuxin Tang, Huaiyu Shao
The successive introduction of silicon (Si) graphite composite anodes into the global market highlights the tremendous commercial potential of Si anodes. Good kinetic performance related to fast charging capability is...
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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D4EE05070C, PaperZhenmin Zhao, Sein Chung, Lixing Tan, Jingjing Zhao, Yuan Liu, Xin Li, Liang Bai, Hyunji Lee, Minyoung Jeong, Kilwon Cho, Zhipeng Kan
The order of molecular aggregation at the donor-acceptor interface strongly affects the charge generation and extraction properties, determining the performance of organic electronic devices. Herein, we focused on bilayer organic...
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Symmetric Quantum Computation

A central challenge in quantum computing is to discern which types of problems allow for quantum algorithms that substantially outperform classical ones. Underlying this challenge is an even more fundamental question: what general characteristics of computational problems make them more (or less) amenable to quantum methods? In this talk I will present my personal attempts to make progress on this fundamental question.

I will introduce a new framework of quantum computation where the symmetries of the problem in consideration play a key role. This framework was developed with the view to elucidate the role of symmetries on quantum speedups, and forms a natural quantum extension of symmetric threshold circuits—a common core where multiple notions of symmetry in classical computation converge. I aim to motivate our computational model and show how it can go beyond the capabilities of its classical counterpart. Several open problems will be presented, which I hope can pave the way for future progress on my earlier question.

This talk is based on joint work with Tom Gur and Sergii Strelchuk.

• Speaker: Davi Castro-Silva (Cambridge)
• Tuesday 11 February 2025, 14:00-15:00
• Venue: Computer Laboratory, William Gates Building, Room FW09.
• Series: Quantum Computing Seminar; organiser: Tom Gur.

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Lewis Lectures 2025 - Lecture II - "Tales of the Unexpected: New Perspectives on Electrochemistry at Carbon Electrodes and Membranes"

A wide variety of carbon materials are used in electrochemistry, with diverse applications that include (bio)electroanalysis and sensors, batteries and fuel cells, and membranes. The family of carbon materials is broad, spanning sp2 and sp3 materials, and includes 1D carbon nanotubes, 2D graphene (and non-carbon analogues) and 3D graphite and conducting diamond, along with amorphous carbon and various composites. The electronic properties of each of these materials are further influenced by local structure and defects, method of preparation, and (for 1-D and 2-D materials) the conducting support, the number of layers, and their arrangement. Ultimately, all of these factors can influence interfacial charge transfer and electrochemistry. In this lecture, I shall discuss our work in this area, which has established a new paradigm for structure-activity across a wide range of carbon materials and electrochemical processes. We combine high resolution electrochemical imaging data with information from other microscopy and spectroscopy techniques applied to the same area of an electrode surface, in a correlative-electrochemical microscopy approach, to produce highly resolved and unambiguous pictures of electrode activity at the nanoscale. The new models of electrochemistry offer surprises, overturn longstanding dogma, unify observations across length scales, and provide a foundation for future rational applications of carbon electrodes.

• Speaker: Prof. Patrick Unwin, University of Warwick
• Friday 28 February 2025, 14:00-15:00
• Venue: Dept of Chemistry, Wolfson Lecture Theatre .
• Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.

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