B18-Core EXAFS
I20-EDE-Energy Dispersive EXAFS (EDE)
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Wenyuan
Huang
,
Bing
An
,
Zeyu
Chen
,
Yu
Han
,
Yinlin
Chen
,
Jiangnan
Li
,
Xue
Han
,
Shaojun
Xu
,
Danielle
Crawshaw
,
Evan
Tillotson
,
Sarah J.
Haigh
,
Bing
Han
,
Christopher M. A.
Parlett
,
Luke
Keenan
,
Svemir
Rudic
,
Yongqiang
Cheng
,
Ben F.
Spencer
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[28575, 31729]
Open Access
Abstract: The development of earth-abundant metal-based catalysts is an important goal for the synthesis of fine chemicals. Here, an active nickel catalyst supported on a robust metal–organic framework, MFM-300(Cr), is reported which shows an exceptional performance for reductive amination, a reaction that has long been dominated by noble metals. Ni/MFM-300(Cr) promotes the synthesis of 38 primary amines via reductive amination of their parent carbonyl compounds, including biomass-derived aldehydes and ketones, using NH3 in the presence of H2 operating under relatively mild conditions (5 bar and 160 °C). X-ray absorption spectroscopy confirms the formation of mixtures of metallic Ni0 and Nin+ active sites, while in situ inelastic neutron scattering, coupled with modeling, reveals details of the mechanism of catalysis involving the formation of N-benzyl-1-phenylmethanediamine (BPDI) as an intermediate species in the generation of benzylamine. Cooperativity between Ni sites and MFM-300(Cr) creates an optimal microenvironment for the efficient activation of carbonyl compounds and the selective production of primary amines using a non-precious metal-based catalyst.
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Oct 2025
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I18-Microfocus Spectroscopy
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Jiayi
Guan
,
Bihan
Wang
,
Nana
Li
,
Shang
Peng
,
Ganghua
Zhang
,
Limin
Yan
,
Xuqiang
Liu
,
Kai
Zhang
,
Mingtao
Li
,
Adama
N-Diaye
,
Qingyu
Kong
,
Dongzhou
Zhang
,
Xu
Zhao
,
Ting
Liu
,
Kejun
Bu
,
Yuhong
Mao
,
Gui
Wang
,
Xujie
Lü
,
Xiang
Li
,
Tao
Zeng
,
Wenge
Yang
Open Access
Abstract: Multiferroic ferroelectric photovoltaic (FPV) materials, combining magnetic and ferroelectric properties, are of paramount importance for optoelectronic and photovoltaic applications. However, optimizing both the remanent polarization and the optical bandgap—key factors for enhanced FPV performance—presents a significant challenge due to their trade-off. This work shows that pressure-induced charge transfer between different metal sites can break this trade-off. Above ≈20 GPa, charge transfer between different trivalent iron (Fe) sites in the multiferroic material BaFe4O7 leads to Fe valence disproportionation, FeO4 tetrahedra disorder, and Jahn–Teller distortion of FeO6 octahedra. These changes reduce the bandgap, lower resistivity, and enhance ferroelectric polarization, resulting in a 2.5-fold increase in photocurrent. Upon decompression, BaFe4O7 retains an order–disorder structure, optimal ferroelectric and optical properties at ambient conditions. This work provides a novel pathway to simultaneously optimizing ferroelectricity and bandgap via pressure-induced charge transfer, overcoming the traditional trade-off in FPV materials, and offers a promising approach for developing high polarization performance, narrow-bandgap FPV materials.
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Aug 2025
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Haozhe
Zhang
,
Mengqi
Duan
,
Shuai
Guo
,
Renzo
Leeflang
,
Dorottya
Szalay
,
Jiasi
Li
,
Jo-Chi
Tseng
,
Simson
Wu
,
Songhua
Cai
,
Dharmalingam
Prabhakaran
,
Robert A.
Taylor
,
Yiyang
Li
,
Shik Chi Edman
Tsang
Open Access
Abstract: Photocatalytic ammonia decomposition offers a sustainable route for hydrogen production, but its development is limited by low catalytic efficiency and poorly understood mechanisms. Here, a protonated layered perovskite, HPrNb2O7 (HPNO), is reported as an efficient catalyst for ammonia decomposition under mild photo-thermal conditions. Upon exposure to NH3 at elevated temperatures, HPNO promotes the in situ formation and intercalation of hydrazine intermediates within its interlayer galleries, enabled by thermally generated oxygen vacancies and hydrogen bonding. Advanced characterization techniques have been applied to confirm the formation and stabilization of hydrazine. It is also shown that thermal energy prolongs charge carrier lifetimes and enhances oxygen vacancy formation, contributing to a strong photo-thermal synergy. The stabilization of hydrazine intermediate promotes the associative mechanism, lowering the activation barrier, thus leading to an enhanced hydrogen evolution rate of 1311.2 µmol·g−1·h−1 at 200 °C under simulated solar irradiation without any noble metal co-catalyst. This work reveals a distinct, hydrazine-mediated reaction pathway and positions layered protonated perovskites as promising materials for efficient, solar-driven ammonia decomposition and sustainable hydrogen generation.
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Aug 2025
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E01-JEM ARM 200CF
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Emerson C.
Kohlrausch
,
Sadegh
Ghaderzadeh
,
Gazi N.
Aliev
,
Ilya
Popov
,
Fatmah
Saad
,
Eman
Alharbi
,
Quentin M.
Ramasse
,
Graham A.
Rance
,
Mohsen
Danaie
,
Madasamy
Thangamuthu
,
Mathew
Young
,
Richard
Plummer
,
David J.
Morgan
,
Wolfgang
Theis
,
Elena
Besley
,
Andrei N.
Khlobystov
,
Jesum
Alves Fernandes
Diamond Proposal Number(s):
[37379, 38763]
Open Access
Abstract: 2D metal clusters maximize atom–surface interactions, making them highly attractive for energy and electronic technologies. However, their fabrication remains extremely challenging because they are thermodynamically unstable. Current methods are limited to element-specific binding sites or confinement of metals between layers, with no universal strategy achieved to date. Here, a general approach is presented that uses vacancy defects as universal binding sites to fabricate single-layer metal clusters (SLMC). It is demonstrated that the density of these vacancies governs metal atom diffusion and bonding to the surface, overriding the metal's physicochemical properties. Crucially, the reactivity of vacancy sites must be preserved prior to metal deposition to enable SLMC formation. This strategy is demonstrated across 21 elements and their mixtures, yielding SLMC with areal densities up to 4.3 atoms∙nm⁻2, without heteroatom doping, while maintaining high thermal, environmental, and electrochemical stability. These findings provide a universal strategy for stabilizing SLMC, eliminating the need for element-specific synthesis and metal confinement protocols and offering a strategy for efficiently utilizing metals.
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Jul 2025
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[30534]
Open Access
Abstract: A comprehensive understanding of the solid electrolyte interphase (SEI) is crucial for ensuring long-term battery stability. This is particularly pertinent in sodium-ion batteries (NIBs), where the SEI remains poorly understood, and investigations are typically undertaken in half-cell configurations with sodium metal as the counter electrode. Na metal is known to be highly reactive with common carbonate-based electrolytes; nevertheless, its effects on SEI formation at the working electrode are largely unexplored. This work investigates the evolution of the SEI in NIBs during cycling, with an emphasis on the consequences of using a sodium metal counter electrode. Advanced analytical techniques, including hard X-ray photoelectron spectroscopy (HAXPES) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), are used to obtain depth-resolved insights into the chemical composition and structural changes of the SEI on hard carbon anodes during cycling. The findings demonstrate that the cell configuration has a significant impact on SEI evolution and, by extension, battery performance. These findings suggest that full-cell studies are necessary to better simulate practical operating conditions, challenging traditional half-cell experiments.
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Jun 2025
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[31918]
Open Access
Abstract: The discovery of ferroelectric phases in HfO2-based films has reignited interest in ferroelectrics and their application in resistive switching (RS) devices. This study investigates the pivotal role of electrodes in facilitating the Schottky-to-Ohmic transition (SOT) observed in devices consisting of ultrathin epitaxial ferroelectric Hf0.93Y0.07O2 (YHO) films deposited on La0.67Sr0.33MnO3-buffered Nb-doped SrTiO3 (NbSTO|LSMO) with Ti|Au top electrodes. These findings indicate combined filamentary RS and ferroelectric switching occurs in devices with designed electrodes, having an ON/OFF ratio of over 100 during about 105 cycles. Transport measurements of modified device stacks show no change in SOT when the ferroelectric YHO layer is replaced with an equivalent hafnia-based layer, Hf0.5Zr0.5O2 (HZO). However, incomplete SOT is observed for variations in the top electrode thickness or material, as well as LSMO electrode thickness. This underscores the importance of employing oxygen-reactive electrodes and a bottom electrode with reduced conductivity to stabilize SOT. These findings provide valuable insights for enhancing the performance of ferroelectric RS devices through integration with filamentary RS mechanism.
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Jan 2025
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I09-Surface and Interface Structural Analysis
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Zhilin
Liang
,
Abdulaziz
Baubaid
,
Mariusz
Radtke
,
Maximilian
Mellin
,
Clément
Maheu
,
Sandipan
Maiti
,
Hadar
Sclar
,
Igor
Píš
,
Silvia
Nappini
,
Elena
Magnano
,
Federica
Bondino
,
Robert
Winkler
,
René
Hausbrand
,
Christian
Hess
,
Lambert
Alff
,
Boris
Markovsky
,
Doron
Aurbach
,
Wolfram
Jaegermann
,
Gennady
Cherkashinin
Diamond Proposal Number(s):
[31579]
Open Access
Abstract: The design of cathode/electrolyte interfaces in high-energy density Li-ion batteries is critical to protect the surface against undesirable oxygen release from the cathodes when batteries are charged to high voltage. However, the involvement of the engineered interface in the cationic and anionic redox reactions associated with (de-)lithiation is often ignored, mostly due to the difficulty to separate these processes from chemical/catalytic reactions at the cathode/electrolyte interface. Here, a new electron energy band diagrams concept is developed that includes the examination of the electrochemical- and ionization- potentials evolution upon batteries cycling. The approach enables to forecast the intrinsic stability of the cathodes and discriminate the reaction pathways associated with interfacial electronic charge-transfer mechanisms. Specifically, light is shed on the evolution of cationic and anionic redox in high-energy density lithium-rich 0.33Li2MnO3·0.67LiNi0.4Co0.2Mn0.4O2 (HE-NCM) cathodes, particularly those that undergo surface modification through SO2 and NH3 double-gas treatment to suppress the structural degradation. The chemical composition and energy distribution of the occupied and unoccupied electronic states at the different charging/discharging states are quantitatively estimated by using advanced spectroscopy techniques, including operando Raman spectroscopy. The concept is successfully demonstrated in designing artificial interfaces for high-voltage olivine structure cathodes enabling stable battery operation up to 5.1 V versus Li+/Li.
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Dec 2024
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[25602]
Open Access
Abstract: By developing a 3D X-ray modeling and spatially correlative imaging method for fibrous collagenous tissues, this study provides a comprehensive mapping of nanoscale deformation in the collagen fibril network across the intact bone-cartilage unit (BCU), whose healthy functioning is critical for joint function and preventing degeneration. Extracting the 3D fibril structure from 2D small-angle X-ray scattering before and during physiological compression reveals of dominant deformation modes, including crystallinity transitions, lateral fibril compression, and reorientation, which vary in a coupled, nonlinear, and correlated manner across the cartilage-bone interface. A distinct intermolecular arrangement of collagen molecules, and enhanced molecular-level disorder, is found in the cartilage (sliding) surface region. Just below, fibrils accommodate tissue strain by reorientation, which transitions molecular-level kinking or loss of crystallinity in the deep zone. Crystalline fibrils laterally shrink far more (20×) than they contract, possibly by water loss from between tropocollagen molecules. With the calcified plate acting as an anchor for surrounding tissue, a qualitative switch occurs in fibrillar deformation between the articular cartilage and calcified regions. These findings significantly advance this understanding of the complex, nonlinear ultrastructural dynamics at this critical interface, and opens avenues for developing targeted diagnostic and therapeutic strategies for musculoskeletal disorders.
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Nov 2024
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I15-Extreme Conditions
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Diamond Proposal Number(s):
[34299]
Open Access
Abstract: The introduction of porosity into ferroelectric ceramics can decrease the effective permittivity, thereby enhancing the open circuit voltage and electrical energy generated by the direct piezoelectric effect. However, the decrease in the longitudinal piezoelectric coefficient (d33) with increasing porosity levels currently limiting the range of pore fractions that can be employed. By introducing aligned lamellar pores into (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3, this paper demonstrates an unusual 22–41% enhancement in the d33 compared to its dense counterpart. This unique combination of high d33 and a low permittivity leads to a significantly improved voltage coefficient (g33), energy harvesting figure of merit (FoM33) and electromechanical coupling coefficient (
). The underlying mechanism for the improved properties is demonstrated to be a synergy between the low defect concentration and high internal polarizing field within the porous lamellar structure. This work provides insights into the design of porous ferroelectrics for applications related to sensors, energy harvesters, and actuators.
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Aug 2024
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[20426]
Open Access
Abstract: Replicating the microstructural basis and the near 100% excitation energy transfer efficiency in naturally occurring light-harvesting complexes (LHCs) remains challenging in synthetic energy-harvesting devices. Biological photosynthesis regulates active ensembles of light-absorbing and funneling chlorophylls in proteins in response to fluctuating sunlight. Here, use of long-range liquid crystal (LC) ordering to tailor chain orientation and packing structure in liquid crystalline conjugated polymer (LCCP) layers for bio-mimicry of certain structural basis and light-harvesting properties of LHCs is reported. It is found that long-range orientational ordering in an LC phase of poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) copolymer stabilizes a small fraction of randomly-oriented F8BT nanocrystals dispersed in an amorphous matrix of F8BT chains, resembling a self-doped host–guest system whereby excitation energy funneling and photoluminescence quantum efficiencies are enhanced significantly by triggering 3D donor-to-acceptor Förster resonance energy transfer (FRET) and dominant intrachain emission in the nano-crystal acceptor. Further, photoalignment of nematic F8BT layers is combined with LC orientational ordering to fabricate large-area-extended monodomains exhibiting >60% crystallinity and ≈20 nm-long interchain packing order. Remarkably, these monodomains demonstrate strong linearly polarized emission, whilst also promoting a new band-edge absorption species and an extra emissive interchain excited state as compared to the non-aligned films.
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Aug 2024
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