B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS
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Diamond Proposal Number(s):
[36218]
Open Access
Abstract: Controlling the redox landscape of transition metal oxides is central to advancing their reactivity for heterogeneous catalysis or high-performance gas sensing. Here, we report single Cu atom sites (1.42 wt.%) anchored on Co3O4 nanoparticles (Cu1-Co3O4) that dramatically enhance reactivity and molecular sensing properties of the support at low temperature. The Cu1 are identified by x-ray absorption near edge structure and feature metal–support interaction between the atomically dispersed Cu (mostly in 2+ oxidation state) and Co3O4, as revealed by x-ray photoelectron spectroscopy. The ability of Cu1 to form interfacial Cu–O–Co linkages strongly reduces the temperature of lattice oxygen activation compared to CuO nanoparticles on Co3O4 (CuONP-Co3O4), as demonstrated by temperature-programmed reduction and desorption analyses, in agreement with density functional theory calculations. To demonstrate practical impact, we deploy Cu1-Co3O4 nanoparticles as a chemoresistive sensor for formaldehyde that yields more than an order of magnitude higher response than CuONP-Co3O4 and consistently outperforms state-of-the-art sensors. Formaldehyde is detected down to 5 parts-per-billion at 50% relative humidity and 75°C with excellent selectivity over critical interferents. These results establish a strategy for activating redox-active supports using single-atom isolates of non-noble nature, yielding drastically enhanced and well-defined reactivity to promote low-temperature oxidation reactions and selective analyte sensing.
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Apr 2026
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I20-Scanning-X-ray spectroscopy (XAS/XES)
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Yuvraj
Vaishnav
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Mohamad
Abou-Daher
,
Cristina I. Q.
Silva
,
Rohit K.
Rai
,
Walid
Al Maksoud
,
Marcell
Toth
,
Mohandoss
Viswanathan
,
Peng
Ren
,
Fumitaka
Takeiri
,
Shusaku
Hayama
,
Samy
Ould-Chikh
,
Mohamed Nejib
Hedhili
,
Maxim
Avdeev
,
Wen
Yin
,
Saburo
Hosokawa
,
Genki
Kobayashi
,
Isaac
Abrahams
,
Aamir
Farooq
,
Javier
Ruiz-Martinez
,
Yoji
Kobayashi
Diamond Proposal Number(s):
[31497]
Open Access
Abstract: High-entropy oxides are attracting attention for catalysis, but there are relatively few detailed studies on their precise structure, hampering true detailed studies on fundamental properties affecting their activities. In addition, diffusion has been often characterized as generally slow in high-entropy systems. Here, we determine the precise oxygen content and structure of the fluorite-like high-entropy oxide (La, Ce, Pr, Nd, Y)O1.68 and have identified a large oxygen storage capacity based on efficient Ce/Pr redox due to facile oxide diffusion pathways and suppression of sintering. The structure and composition were identified through a combined Rietveld refinement of X-ray and neutron diffraction data, and the oxidation state of Ce and Pr was investigated by high energy resolution fluorescence detected–X-ray absorption near edge spectra (HERFD–XANES). (La, Ce, Pr, Nd, Y)O1.68 utilizes the full redox range of Ce/Pr, resulting in a high oxygen storage cumulative capacity despite the lower content of Ce/Pr compared to other well-known ceria derivatives. Diffusion pathway analysis by bond valence site energy mapping shows decreased barriers for oxide anion diffusion through the bulk, also benefiting redox reactions. The high-entropy nature also suppresses sintering, resulting in better cycling performance. This results in a higher performance as a methane oxidation catalyst support. We also investigate its use as a NOx reduction catalyst support.
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Mar 2026
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[33261]
Open Access
Abstract: Lithium metal (LM) and zero-excess lithium (ZE) anodes offer pathways to increase the energy density of all-solid-state batteries (ASSBs). We employ operando X-ray computed tomography combined with an image subtraction method to visualize lithium plating/stripping morphology, stack mechanical failure, and quantify the lithium reversibility in asymmetric Li6PS5Cl (LPSC)-based ASSBs. Lithium metal counter electrode (CE) and copper (Cu) working electrode (WE) emulate LM and ZE interface configurations, respectively. We compare bare Cu and silver-coated Cu (Ag/Cu) WEs under varying current densities. At 0.25 mA cm−2(WE), bare Cu shows edge-localized and non-uniform lithium deposition, while Ag/Cu facilitates more uniform lithium spreading, but results in higher first-cycle irreversibility and lower Coulombic efficiency. Above 0.5 mA cm−2(WE), failure in Li|LPSC|Cu cells initiate at the LPSC|Cu interface via spallation cracks. In contrast, Ag preserves interface integrity at the WE despite lithium initially plates at discrete nucleation spots. However, failure shifts to the Li|LPSC interface, where non-uniform lithium depletion at the CE exposes the underlying Cu, leading to spallation cracks upon subsequent plating. Mechanical finite element simulations support these observations and underscore the critical role of the nucleation layers in mitigating mechanical failure. This study highlights interface engineering as a key strategy to address electro-chemo-mechanical degradation in LM- and ZE-ASSBs.
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Jan 2026
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E02-JEM ARM 300CF
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Diamond Proposal Number(s):
[37041, 56733]
Open Access
Abstract: 2D Prussian blue and its analogues hold great promise for applications in catalysis, energy conversion, sensing, and memory devices, thanks to their open frameworks, surface activity, and directional ion transport. However, synthesizing high-quality and large-area 2D films remains a major challenge. Here, we present a robust and scalable liquid-liquid interfacial synthesis that enables the formation of continuous, 2D flakes of Prussian blue (Fe3+[Fe2+(CN)6]0.75) with tunable thicknesses from ∼2 nm to several hundred nanometers. The controlled reduction of [Fe3+(CN)6]3− to [Fe2+(CN)6]4− enables slow, directed growth of 2D-FeFe layers. Unlike films formed from nanoparticles, this method yields high-quality flakes suitable for integration into devices. As a demonstration, we incorporated these films into Ag filament-based electrochemical metallization memristors. The 2D-FeFe devices ≥50 nm thick exhibited reliable bipolar electrical switching, with high Roff/on ratios (∼106), >6 h retention, and stability over 150 cycles. Strikingly, switching was observed across 1.5 µm lateral gaps, far exceeding conventional silver filament formation distances, highlighting the superior ion transport and structural integrity of these 2D frameworks. This scalable approach to 2D Prussian blue, which has the potential to be extended to other related coordination polymers, offers exciting opportunities beyond memristors, enabling integration into technologies where thin-film compatibility, directional ion transport, and high surface activity are critical, such as catalysis, energy storage, and neuromorphic computing.
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Jan 2026
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B21-High Throughput SAXS
I22-Small angle scattering & Diffraction
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Abdulwahhab
Khedr
,
Mohamed A. N.
Soliman
,
Alfred
Corrigan
,
Tarsem
Sahota
,
Rachel
Armitage
,
Natalie
Allcock
,
Jeyapriya T.
Jegadeesan
,
Mahetab H.
Amer
,
Reem
Alazragi
,
Zeeshan
Ahmad
,
Jacek K.
Wychowaniec
,
Mohamed A.
Elsawy
Diamond Proposal Number(s):
[28287, 28806]
Open Access
Abstract: Multicomponent peptide nanostructures offer a powerful platform for designing functional materials, yet controlling their co-assembly remains a key challenge. Here, we harness electrostatic molecular recognition to drive the selective co-assembly of five amphiphilic ionic peptide binary mixtures (M1–M5). Our results revealed that charge distribution governs β-sheet strand alignment (parallel vs. antiparallel), assembly kinetics, and hydrogel viscoelasticity. Mixing stoichiometry and pH significantly influences co-assembly behavior, nanofiber morphology, and network structure (self-sorted vs. hetero-aggregated). At pH 7, equimolar mixtures undergo nucleation-driven co-assembly into hetero-aggregates, immediately forming well-defined nanofibers, while non-equimolar ratios yield altered morphologies. At a slightly acidic pH of 5–7, both E and K side chains are charged, enabling complementary ionic interactions that promote co-assembly and gelation. Outside this pH range, co-assembly is impaired. Notably, M1 forms β-sheets and hydrogels at acidic pH (≤4) via independent self-assembly of its components, suggesting self-sorted fibers. Overall, we demonstrate that tuning charge complementarity, ionization state, and stoichiometry enables precise control over the molecular, nanoscale, and mechanical properties of multicomponent peptide assemblies, providing a framework for the rational design of advanced peptide-based materials.
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Jan 2026
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E01-JEM ARM 200CF
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Diamond Proposal Number(s):
[33481]
Open Access
Abstract: A novel heterostructured hexagonal-boron nitride (h-BN) flake-coating on multi-wall carbon nanotubes (MWCNT/BN) is reported and synthesized by chemical vapor deposition (CVD). Comprehensive characterization using X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM), combined with electron energy loss spectroscopy (EELS), revealed the atomic structure and growth mechanism, which is further validated by molecular dynamics simulations. The resulting MWCNT/BN structure comprises three distinct layers: an inner carbon nanotube (CNT) core, coaxial BN nanotubes (BNNTs) surrounding the CNT core, and outer BN flakes extending from the BNNTs. We propose that BN layers first form coaxial BNNTs on the CNT surface; as deposition proceeds, BN accumulation generate in-plane and out-of-plane compressive stresses in the h-BN layers. When these stresses exceed a critical threshold, local buckling or cracking occurs, BN flakes emerge and grow further. This work elucidates, for the first time, the formation mechanism of BN nanoflakes on MWCNTs and confirms that the structure is a van der Waals heterostructure. The approach also offers a new route for synthesizing coaxial MWCNT@BN with only a few h-BN layers. Notably, the BN flake coatings provide efficient phonon transport pathways and a large surface area, making this heterostructure highly promising for applications in thermal dissipation.
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Dec 2025
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Open Access
Abstract: Understanding the structure and dynamics of the hydrogen-bond network of water in topologically distinct swollen lipidic mesophases, is fundamental for their application in biomedical, pharmaceutical, and food science fields. Here, a positive and non-linear correlation between water hydrogen-bond dynamics and interfacial water population is uncovered in inverse bicontinuous swollen mesophases across an extended temperature range (298–340 K). Particularly, small-angle X-ray scattering determines the mesophase's structural features, uncovering a temperature-driven re-entrant phenomenon (reappearance) of
phase upon heating. This topologically rich environment, however, has no detectable impact on the temperature dependence of the intermolecular modes of water, as revealed by terahertz absorption spectroscopy. Specifically, these modes show distinct dynamics: the stretching mode exhibits longer lifetimes than the libration mode, yet with a higher temperature-dependence, with approximately two-fold lower Arrhenius activation energies. In contrast, both stretching and libration modes exhibit a monotonic decrease in lifetime with increasing temperature, due to the increasing disruption of the hydrogen-bond network. Atomistic molecular dynamics simulations enable the quantification of interfacial water population, which shows a positive correlation with intermolecular lifetimes in a nonlinear manner, revealing a non-additive coupling between interfacial water population and water hydrogen-bond network dynamics within these systems.
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Oct 2025
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I19-Small Molecule Single Crystal Diffraction
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Thien D.
Duong
,
Jiangnan
Li
,
Ruohan
Li
,
Xin
Lian
,
Yinlin
Chen
,
Jiarui
Fan
,
Joseph
Hurd
,
Lixia
Guo
,
Daniel
Lee
,
Mark
Warren
,
Sihai
Yang
Diamond Proposal Number(s):
[41123]
Abstract: The capture of xenon (Xe) and krypton (Kr) from the off-gas of used nuclear fuel is of great importance to the treatment of radioactive wastes and production of high purity Xe. Solid sorbents, in particular metal–organic frameworks (MOFs), show promise in gas capture. However, the unknown radiation resistance of MOFs has limited their development. Herein, the efficient capture and separation of Xe/Kr by MFM-520, which strikes a remarkable stability toward 1750 kilogray (kGy) γ-irradiation, is reported. Under ambient conditions, dynamic breakthrough experiments confirm the efficient separation performance, yielding a Xe capacity of 66 and 0.2 mg g−1 from a by-product of air separation (Xe/Kr: 20/80; v/v) and off-gas (Xe/Kr: 400/40 ppm balance in air), respectively. In situ synchrotron X-ray single crystal diffraction and solid-state nuclear magnetic resonance (ssNMR) studies reveal that the optimal micropore of MFM-520 underpins specific host-guest interactions to Xe, resulting in selective Xe capture.
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Oct 2025
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Open Access
Abstract: The MIL-53 series of metal–organic frameworks (MOFs) is considered archetypal for flexible MOFs, with desolvated materials rapidly transitioning between open and closed phases in a stepwise breathing process in response to changes in temperature under ambient pressure conditions. Herein, the differing structures of MIL-53(Cr) and MIL-53(Ga) during breathing – hydrated and anhydrous, closed and open pore–are characterized by in situ single crystal 3D electron diffractionthrough varying sample conditions within the electron diffractometer. In doing so, the crystal structures of nine intermediate phases are uncovered that together represent the continuous breathing of MIL-53 under vacuum, in stark contrast to ambient pressure stepwise breathing. In addition, these structures offer insight into particle-to-particle structural heterogeneity that are averaged out by conventional powder X-ray diffraction measurements, and may begin to explain metal-dependent adsorption phenomena observed across the MIL-53 homologues. In situ 3D electron diffraction is therefore expected to become a powerful tool for in-depth structural investigations of flexible porous materials.
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Oct 2025
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Open Access
Abstract: We present serial electron diffraction with tilt (t-SerialED), a method for fast autonomous phase and structural analysis of beam-sensitive, nano-sized polycrystalline materials. Unlike traditional workflows collecting datasets crystal by crystal, t-SerialED acquires datasets using a batch-by-batch approach, which speeds up the data acquisition. t-SerialED combines robust indexing from 3D reciprocal space with still-shot integration and merging methods from serial crystallography. t-SerialED enables high-throughput analysis of beam-sensitive, multi-phase mixtures across a wide range of materials, from nanoporous frameworks to pharmaceutical compounds. By resolving key challenges in serial crystallography such as indexing and preferred orientation, this method enables precise structure determination, including the visualization of guest molecules and non-covalent interactions like hydrogen bonding and proton charge transfer. Demonstrated on a range of samples from nanoporous materials to pharmaceuticals, t-SerialED expands the capabilities of serial chemical crystallography from single-phase to complex multi-phase systems. It can become a complementary method to traditional crystallography methods, offering a robust solution for routine quantitative phase analysis and structure determination.
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Oct 2025
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