Plasmon-induced resonant energy transfer and flat band formation in Fe and Co doped Ni( <scp>ii</scp> ) hydroxide for efficient photocatalytic oxygen evolution

Physical Chemistry Chemical Physics · 2025-01-01 · 2 citations

LDH) to 2.3 eV and the formation of flat bands was observed, enabling efficient energy transfer upon plasmonic nanoparticle integration and enhancing electronic properties. This supports that the PIRET mechanism is responsible for the increased OER performance. This study demonstrates the crucial role of PIRET in enhancing plasmonic energy transfer and the synergistic effects of doping and AuNP coupling. These findings highlight the broader potential of material engineering in advancing efficient and sustainable energy technologies.

Plasma-assisted reduced graphene oxide-wrapped Ni-rich cathode materials for Li-ion batteries

Chemical Engineering Journal · 2025-10-26 · 1 citations

Ni-rich layered oxides such as Li Ni 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) offer high specific capacity for lithium-ion batteries but exhibit limited rate performance and structural degradation at high voltages. In this study, we present a plasma-assisted strategy to reduce graphene oxide (GO), forming a uniform reduced graphene oxide (rGO) coating on NMC811 particles. The optimized 7 wt% rGO wrapping significantly improves electrochemical performance, delivering an initial discharge capacity of 212 mAh g −1 and retaining 82 % capacity after 100 cycles at 1C. In contrast, pristine NMC811 demonstrates 196 mAh g −1 with 73 % retention under the same conditions. Structural and surface analyses confirm that the rGO wrapping maintains the layered crystal structure and preserves the original oxidation states of transition metals in NMC811. This conformal rGO wrapping also enhances rate capability and high-voltage cycling stability by facilitating lithium-ion diffusion and improving electrode integrity. The surface modification does not significantly alter the bulk properties of NMC811, highlighting the efficiency and scalability of this technique. Our results demonstrate that rGO-based surface engineering offers a promising route to address the intrinsic limitations of Ni-rich cathodes, paving the way for more durable and high-performing lithium-ion batteries. • Nitrogen plasma enables reduction of GO on NMC811 surface without toxic chemical reductants. • Uniform rGO shell enhances conductivity and protects cathode–electrolyte interface. • NMC811/rGO-7 delivers 212 mAh g −1 and 82 % capacity retention after 100 cycles at 1C. • rGO layer suppresses Ni 2+ /Li + cation mixing and phase degradation under high voltage. • Demonstrates a scalable, low-temperature, and sustainable coating strategy for LIBs.

Positron Studies of Defects: Workshop Special Issue

Trans Tech Publications Ltd. eBooks · 2025-07-18

The special edition is devoted to issues related to applying Positron Annihilation Spectroscopy as a nondestructive technique for studying voids and defects in solids. The first chapter contains articles that analyse the features of the latest techniques and instrumentation and present the results of developing some of them. The second chapter is devoted to the practical application of the methods of positron annihilation spectroscopy for studying and analysing defects in alloys, multilayer graphene, photoconductor thin films, complex iron-containing oxide glasses, for the early detection of mental disorders and cancer, etc. Without a doubt, this special edition will be useful for both beginners and professionals with experience in the field of positron annihilation spectroscopy.

Hole and Cusp Formalism in Electron-Positron Density Functional Theory

Diffusion and defect data, solid state data. Part B, Solid state phenomena/Solid state phenomena · 2025-07-18

We investigate the hole formalism and positron screening within the framework of Den sity Functional Theory (DFT). This study revisits the Local Density Approximation (LDA) and its extensions - such as semilocal functionals and the Weighted Density Approximation (WDA), show ing their importance in modeling exchange and correlation potentials. We further examine the two-component density functional approach to describe electron-positron interactions, with particular em phasis on the formation of the electron screening cloud around the positron site. The performance of various computational techniques in describing charge inhomogeneities and positron surface states is critically assessed. Moreover, we identify the limitations of conventional models in low-dimensional systems and propose a novel method based on the electronic dielectric response to improve the accu racy of positron screening predictions.

Critical current density in advanced superconductors

Progress in Materials Science · 2025-05-26 · 23 citations

<p dir="ltr">This review paper delves into the concept of critical current density in high-temperature superconductors (HTS) across macroscopic, mesoscopic, and microscopic perspectives. Through this exploration, a comprehensive range of connections is unveiled aiming to foster advancements in the physics, materials science, and the engineering of applied superconductors. Beginning with the macroscopic interpretation of as a central material law, the review traces its development from C.P. Bean’s foundational work to modern extensions. Mesoscopic challenges in understanding vortex dynamics and their coherence with thermodynamic anisotropy regimes are addressed, underscoring the importance of understanding the limitations and corrections implicit in the macroscopic measurement of , linked with mesoscopic phenomena such as irradiation effects, defect manipulation, and vortex interactions. The transition to supercritical current densities is also discussed, detailing the superconductor behavior beyond critical thresholds with a focus on flux-flow instability regimes relevant to fault current limiters and fusion energy magnets. Enhancing through tailored material microstructures, engineered pinning centers, grain boundary manipulation, and controlled doping is explored, along with radiation techniques and their impact on large-scale energy systems. Emphasizing the critical role of , this review focuses on its physical optimization and engineering manipulation, highlighting its significance across diverse sectors.

Accelerating materials discovery for water crisis: Multi-objective machine learning for atmospheric water harvesting by MOFs

Materials Today Communications · 2025-10-13 · 1 citations

<title>Abstract</title> Addressing the global water crisis requires efficient water supply solutions. Metal-organic frameworks (MOFs) offer promise for atmospheric water harvesting (AWH). However, many MOFs suffer from poor water stability or limited adsorption capacity. To accelerate discovery, we conceptualize structure–property relationships and develop an artificial intelligence-based multi-objective workflow that evaluates MOF water uptake at low and high relative humidity, water selectivity, and stability. A wide range of classification and regression models, hyperparameter spaces, and feature selection methods are tested, with the light gradient boosting machine (LGBM) model achieving the best performance. Results reveal that water uptake and selectivity depend mainly on structural features while chemical features dominate stability. The workflow is validated on benchmark water-harvesting MOFs and newly reported stable structures. We identify the top 100 MOFs as leading AWH candidates and propose design rules to guide experimental efforts and new research directions. The workflow is available as AquaMOF, a user-friendly software package with a web interface (https://aquamof.website/), enabling on-the-fly predictions of the AWH potential of new MOFs.

Recycling Failed Photoelectrons for Coherent Photoemission From Flat-band Quantum Materials

SSRN Electronic Journal · 2025-01-01

First-principles study of positron interface states in graphene-stacked LiCoO2 Cathodes

Electrochimica Acta · 2025-04-06 · 6 citations

Positron quantum probe diagnosis at the cathode/graphite interface in a Co-free Ni-based cathode to optimize Li-ion mobility

Sustainable materials and technologies · 2025-10-01

Lithium-ion batteries (LIBs) are among the most promising power sources covering a wide range of applications by persistent de-bottlenecking the low electrical conductivity and Li-ion diffusivity of the cathode. This study proposes a cobalt-free, nickel oxide-based cathode, addressing the sustainable concerns associated with cobalt reduction or elimination. Coating the cathode micro-particles with carbon is a common approach for improving the electric conductivity and structural stability against cycling-induced degradation. Using positron annihilation lifetime spectroscopy (PALS) as a quantum probe of interfacial interactions, complemented by advanced density functional theory simulations, we investigated the role of carbon layer boosting the Li-ion mobility for fast charging. PALS results obtained in LiNiO 2 reveal that the presence of filaments into the cathode grain microstructure, combined with the carbon capping layer, enhances positron mobility. Therefore, PALS can be used as a sensitive diagnostic tool, providing detailed insights for optimizing interfacial Li-ion dynamics to advance the development of fast-charging batteries for the future. • Influence of carbon additives on Co-free Ni-based cathodes. • Positrons as quantum probes in battery cathodes. • Enhanced charge mobility in a LiB cathode through carbon additives.

The International Workshop on Positron Studies of Defects (PSD-24)

Trans Tech Publications Ltd. eBooks · 2025-07-30

Following a standing tradition that began in 1987 in Germany, The International Workshop on Positron Studies of Defects (PSD-24) was held in the Sala Bianca of the Teatro Sociale di Como, Italy, from September 1 to 6, 2024.The workshop aimed to provide a platform for the exchange of the latest scientific results and developments concerning positron interactions with solids and surfaces, the applied techniques, and their diverse applications. An intensive two-day Summer School in honour of Alfredo Dupasquier was held at the Brunate Library on August 31st and September 1st, prior to the PSD-24. The School featured lectures delivered by leading international experts in Positron Annihilation Spectroscopy (PAS).