B18-Core EXAFS
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Open Access
Abstract: Metal nanoparticles are widely considered for heterogeneous catalysis due to their high atomic efficiency and tunable active microenvironment, but their specific functional tendencies are still unclear. Here, we report that a Rh@ZrO2/NC catalyst with only 0.1 wt% Rh exhibits exceptional catalytic performance and high selectivity (p-nitroacetophenone conversion-98.6 %, p-aminoacetophenone selectivity-100 %, r-56.4 molp-nitroacetophenone/(molRh·min)) towards the hydrogenation of the -NO2 group in nitroarene to -NH2. This is because the interaction between Rh species and “ZrO2-N” results in significant hydrogen spillover in the catalyst, as supported by DFT calculations. Extensive characterizations from TG, DTG, NAP-XPS, in-situ Raman spectroscopy, in-situ DRIFT spectroscopy and DFT calculations further confirm the adsorption, activation and dissociation of hydrogen on Rh nanoparticles. The H* species migrate readily over ZrO2-NC, to facilitate the catalytic activity and selectivity for the hydrogenation of nitroarene. This study presents a new approach to develop highly efficient and selective metal nanoparticle-catalysts for cost-effective hydrogenation reactions.
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Dec 2025
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Abstract: The low-temperature performance of mixed-composition perovskite solar cells (PSCs) reflects the complex interplay among thermal effects, bandgap renormalization, and structural phase behavior. Temperature-dependent structural, optical, and electrical measurements reveal a maximum power conversion efficiency at 263 K, which coincides with the onset of the cubic-tetragonal phase coexistence. At this temperature, symmetry lowering is observed, accompanied by a split emission band and increased current–voltage hysteresis, consistent with structural heterogeneity. Device simulations show that any benefit from mixed-phase band alignment is conditional on effective interphase passivation. Consequently, the mixed phase is best described as a loss-minimum condition at well-passivated cubic–tetragonal interphases with stable collection. Our findings identify a narrow mixed-phase window in which phase coexistence couples to the optoelectronic response and enhances the device performance, providing fundamental insight into temperature-dependent structure–property relations in hybrid perovskites.
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Dec 2025
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DIAD-Dual Imaging and Diffraction Beamline
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Loris
Chavée
,
Emile
Haye
,
Jochen M.
Schneider
,
Stanislav
Mráz
,
Andreas
Pflug
,
Dennis
Barton
,
Armel
Descamps
,
Claudie
Josse
,
Jérôme
Müller
,
Pavel
Moskovkin
,
James
Marrow
,
Amael
Caillard
,
Stephane
Lucas
Diamond Proposal Number(s):
[34010]
Abstract: The deposition of functional coatings on open-cell foam substrates using magnetron
sputtering is gaining popularity, particularly for applications like Oxygen Evolution
Reaction (OER)/Hydrogen Evolution Reaction (HER) catalysis, batteries, and
supercapacitors. While most research focuses on performance, little attention has
been paid to the coating growth mechanisms or properties within the foam, which could
significantly impact device performance. This work investigates the properties and
growth mechanisms of TiO₂ coatings inside porous foams, using experimental and
modeling techniques.
The structure, composition and thickness of the coating on the outermost surface of
the foam are studied using Focused Ion Beam (FIB), Scanning Transmission Electron
Microscopy (STEM), Energy-Dispersive X-Ray Spectroscopy (EDS), Selected Area
Electron Diffraction (SAED) and High-Resolution Transmission Electron Microscopy
(HRTEM). The experimental results reveal the formation of a dense, (quasi-
)stoichiometric and crystalline coating.
Numerical simulations and experiments highlight the transport of plasma particles in
the foam. Interestingly, Direct Simulation Monte Carlo (DSMC)/Particle-In-Cell Monte
Carlo (PICMC) models, coupled with Mass-Energy Analyzer (MEA) experiments,
demonstrate that the particle flux is reduced, but the particle energy distribution is not
Accepted Manuscript affected while traveling inside the foam. Using kinetic Monte Carlo (kMC) thin film
growth models provided by Virtual CoaterTM, the physical properties of the coating
inside the foam have been modeled, and the drop in coating thickness as well as the
impact of bias voltage on densification, resistivity, and optical absorption are
confirmed. Synchrotron X-Ray Diffraction (SXRD) analyses of the foam demonstrate
that the same crystalline phase is obtained along the foam thickness, but it can be
tailored with bias voltages. The decrease in the recorded SXRD signal with increasing
depth inside the foam also suggests a drop in coating thickness.
The new insights on the properties of coatings inside open-cell foams presented in this
study can be used to improve future foam-based devices.
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Dec 2025
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I07-Surface & interface diffraction
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Chieh-Szu
Huang
,
Danbi
Kim
,
Wenyan
Yang
,
Yang
Lu
,
Robert J. E.
Westbrook
,
Huagui
Lai
,
Zimu
Wei
,
Chaeyeon
Lee
,
Fan
Fu
,
Neil C.
Greenham
,
Bo Ram
Lee
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[32266]
Open Access
Abstract: Amphiphilic polymer conetworks (APCNs), composed of nanoscale phase-separated hydrophilic and hydrophobic domains, have recently attracted interest for passive photonic applications like wearable luminescent solar concentrators. Here, their utility is extended by integrating APCNs into the active layer of organic photovoltaics (OPVs), enabling the incorporation of down-conversion luminophores that are otherwise incompatible with conventional OPV architectures. The APCN scaffold confines hydrophilic luminophores within hydroxyl acrylate domains, while the hydrophobic PM6:Y6 bulk heterojunction (BHJ) resides in the polydimethylsiloxane domains. Luminophores are chosen for selective phase affinity and complementary absorption to the BHJ. Devices incorporating dicyanomethylene-4H-pyran (DCM) luminophores show enhanced photocurrent, with short-circuit current increasing from 25.7 to 27.3 mA cm−2, while maintaining an open-circuit voltage of 0.86 V. Transient absorption spectroscopy reveals delayed ground-state bleach in PM6 and Y6, consistent with efficient exciton replenishment via energy transfer from luminophores. Grazing-incidence wide-angle X-ray scattering shows that luminophore molecular planarity and dihedral angles influence BHJ packing via van der Waals interactions, impacting charge transport. This work presents a multifunctional approach to enhance optoelectronic devices by embedding functional moieties within APCNs, offering insights from photonic, optoelectronic, and structural perspectives and establishing APCNs as a versatile platform for next-generation device engineering.
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Nov 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Emily C.
Giles
,
Abbey
Jarvis
,
Pierrot S.
Attidekou
,
Kieran
O'Regan
,
Rosie
Madge
,
Alexander T.
Sargent
,
Beatrice
Browning
,
Anton
Zorin
,
Roberto
Sommerville
,
Alex J.
Green
,
Stefan
Michalik
,
Philip A.
Chater
,
Daniel
Reed
,
Emma
Kendrick
,
Laura L.
Driscoll
,
Peter
Slater
,
Phoebe K.
Allan
,
Paul
Anderson
,
Luke
Sweeney
Open Access
Abstract: Understanding the degradation of large format lithium-ion pouch cells – critical for electric vehicle applications – is vital to extend their lifetime and allow potential second-life application. Here, the impact on capacity fade and material degradation in two end-of-life cells, which were additionally subjected to accelerated aging to mimic extended use in second-life applications, were examined using powder synchrotron X-ray diffraction, Raman spectroscopy and electrochemical impedance spectroscopy, complemented by detailed post mortem analyses. The dominant mechanism of capacity loss under these conditions was found to be lithium inventory depletion, driven by processes such as electrolyte decomposition, lithium plating and solid electrolyte interphase growth. Structural changes in the graphite anode, including amorphization and reduced active material, were more pronounced under severe overcharging conditions. The blended cathode showed lithium inventory loss in both phases, but 92–94% capacity recovery was observed on subsequent cycling in half cells vs Li, illustrating its robustness, with little structural degradation observed. The finding that electrolyte degradation/loss in these cells was a more critical contributor to cell degradation toward the knee-point than electrode active material degradation/loss indicates that increasing – or replenishing – the electrolyte content could be a strategy to extend the usable life of such cells.
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Nov 2025
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[35733]
Open Access
Abstract: This research examines the dynamics of reactive CO2 transport in carbonate rock, focusing on the impact of carbonic acid-induced formation damage. We provide real-time visualization of these processes by employing four-dimensional (4D) high-resolution synchrotron imaging at the I13 beamline hosted at the Diamond Light Source. We visualize and quantify the temporal effects of reactive CO2 transport at the pore scale in carbonate rock. The experiment involved injecting CO2-saturated brine through the sample with in situ scanning to track the different stages of chemical dissolution. Analysis of the images shows a channelled dissolution pattern which corresponds with a gradual increase in porosity due to pore structure changes. Pore network models were generated from the segmented images to carry out a sequence of drainage and imbibition simulations. The result demonstrated that reduced capillary entry pressure with increased pore connectivity after dissolution. Furthermore, the trapping efficiency was quantified to predict a slight decrease in dissolution as the pores become broader and better connected.
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Oct 2025
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Emma
Van Der Minne
,
Priscila
Vensaus
,
Vadim
Ratovskii
,
Seenivasan
Hariharan
,
Jan
Behrends
,
Cesare
Franchini
,
Jonas
Fransson
,
Sarnjeet S.
Dhesi
,
Felix
Gunkel
,
Florian
Gossing
,
Georgios
Katsoukis
,
Ulrike I.
Kramm
,
Magalí
Lingenfelder
,
Qianqian
Lan
,
Yury V.
Kolen'Ko
,
Yang
Li
,
Ramsundar Rani
Mohan
,
Jeffrey
Mccord
,
Lingmei
Ni
,
Eva
Pavarini
,
Rossitza
Pentcheva
,
David H.
Waldeck
,
Michael
Verhage
,
Anke
Yu
,
Zhichuan J.
Xu
,
Piero
Torelli
,
Silvia
Mauri
,
Narcis
Avarvari
,
Anja
Bieberle-Hütter
,
Christoph
Baeumer
Open Access
Abstract: A central challenge in water electrolysis lies with the oxygen evolution reaction (OER) where the formation of molecular oxygen (O2) is hindered by the constraint of angular momentum conservation. While the reactants OH− or H2O are diamagnetic (DM), the O2 product has a paramagnetic (PM) triplet ground state, requiring a change in spin configuration when being formed. This constraint has prompted interest in spin-selective catalysts as a means to facilitate OER. In this context, the roles of magnetism and chirality-induced spin selectivity (CISS) in promoting the OER reaction have recently been investigated through both theoretical and experimental studies. However, pinpointing the key principles and their relative contribution in mediating spin-enhancement remains a significant challenge. This roadmap offers a forward-looking perspective on current experimental trends and theoretical developments in spin-enhanced OER electrocatalysis and outlines strategic directions for integrating incisive experiments and operando approaches with computational modeling to disentangle key mechanisms. By providing a conceptual framework and identifying critical knowledge gaps, this perspective aims to guide researchers toward dedicated experimental and computational studies that will deepen the understanding of spin-induced OER enhancement and accelerate the development of next-generation catalysts.
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Oct 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Zixuan
Li
,
Rui
Qi
,
Yi
Yuan
,
Lechen
Yang
,
Lijiang
Song
,
Ashok S.
Menon
,
Louis F. J.
Piper
,
Didier
Wermeille
,
Paul
Thompson
,
Robert A.
House
,
Peter G.
Bruce
,
Alex W.
Robertson
Open Access
Abstract: Aqueous zinc-ion batteries (ZIBs) suffer from sustained capacity loss at the zinc metal anode due to side reactions with the electrolyte, even under idle conditions. The concept of an anode-free ZIB would address this degradation by eliminating the metal anode source. A key requirement for such systems is a cathode that contains zinc in its pristine state and supports initial charging. Here, we report the synthesis and characterization of cation-disordered rocksalt (DRX) ZnMnO2, a new cathode material suitable for anode-free ZIBs. ZnMnO2 meets the essential criteria for anode-free operation of natively containing Zn in the pristine state, enabling an initial charge, as well as offering high initial charge capacity (312.8 mAh g−1), and discharge voltage (1.36 V). We show that the dominant energy storage mechanism involves Mn dissolution and redeposition, with a smaller contribution arising from reversible Zn intercalation into a spinel phase that forms in situ during cycling. We further demonstrate the versatility of DRX cathodes by extending the concept to ZnFeO2. These findings establish DRX materials as a promising platform for the development of cathodes suitable for anode-free ZIBs.
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Oct 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[29820]
Abstract: Non-destructive testing using X-ray computer tomography (XCT) has been used to assess the applicability of visualising ceramic kernels held within a dissimilar ceramic matrix. Simulations were performed to ascertain the feasibility of CT scans of such samples, and optimise the scanning parameters offline. Corresponding experiments were carried out to assess the defects in the structure that exist as a result of manufacturing methods in zirconium diboride (ZrB2) kernels held within a zirconium dioxide (ZrO2) matrix material. Ceramic–ceramic matrix composites are garnering a great deal of interest in a number of applications, including as nuclear fuels for high temperature gas reactors and the methodology presented has potential to be of use in assessing the position and state of pellets incorporated into a ceramic matrix, whilst being able to detect features such as cracks, porosity and interfaces between kernels and the matrix. Computer modelling of the composites supports the experimental observations and has been used to assess the plausibility of assessing a higher density of kernels held within a ceramic matrix that will support ongoing work, whilst highlighting a valid method for periodical assessment of fuel manufacturing processes.
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Sep 2025
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I13-2-Diamond Manchester Imaging
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Iain
Malone
,
Secil
Unsal
,
R. Scott
Young
,
Matthew P.
Jones
,
Francesco
Spanu
,
Shashidhara
Marathe
,
Rhodri
Jervis
,
Hugh G. C.
Hamilton
,
Christopher M.
Zalitis
,
Thomas S.
Miller
,
Alexander J. E.
Rettie
Diamond Proposal Number(s):
[35192]
Open Access
Abstract: Anion exchange membrane water electrolysers are held back by the low durability of the ionomer in the membrane and catalyst layers. Studying ionomer degradation in these systems is challenging because the main mechanisms - which result in catalyst detachment, membrane thinning, and loss of cationic functionality - have opposing effects on the cell potential. Electrochemical measurements alone are therefore insufficient for elucidating the underlying causes of degradation. To address this, a bespoke miniature-electrolyser-cell is developed for X-ray microtomography imaging of membrane electrode assemblies at 1.6 µm resolution. This setup enables the study of the entire active volume of the electrolyser under static and operando conditions and is validated against standard 5 cm2 laboratory cells. An operando investigation of degradation in Fumasep-based catalyst-coated membranes reveals both significant membrane thinning and loss of membrane ionic conductivity during stability testing, leading to increased ohmic resistance and cell potential. In contrast, a Selemion membrane shows minimal changes in thickness and conductivity and is significantly more stable compared to Fumasep when exposed to synchrotron radiation. This platform has relevance for operando studies of electrochemical materials and devices generally, including proton exchange membrane electrolysers, fuel cells, and CO2 electrolysers using both lab-based and synchrotron X-ray sources.
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Sep 2025
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