E02-JEM ARM 300CF
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Jaeho
Lee
,
Wengang
Huang
,
Xiangyi
Zha
,
Xuemei
Li
,
Zixi
Xie
,
Peng
Chen
,
Chenghan
Sun
,
Muhammad Yazid
Bin Zulkifli
,
Sang T.
Pham
,
Bun
Chan
,
Marija
Švegovec
,
Atul
Shukla
,
Junyong
Zhu
,
Rijia
Lin
,
Nicholas M.
Bedford
,
Vicki
Chen
,
Sean
Collins
,
Andraž
Krajnc
,
Anthony K.
Cheetham
,
Lianzhou
Wang
,
Jingwei
Hou
Diamond Proposal Number(s):
[26822]
Open Access
Abstract: Developing quantum dots (QDs) with robust and stable photoluminescence are critical for the advancement of optical nanomaterials. However, QD synthesis still usually involves complex nucleation, growth, surface capping, and separation procedures. Herein, we present an approach to generating embedded PbI2 QDs in situ within the matrix of a metal–organic framework (MOF) glass. This is achieved by controllable decomposition of an optoelectronically inactive δ-phase organic lead halide perovskite (OLHP) within the MOF glass, where the high-temperature MOF melt alters the degradation pathway through interfacial bonding and dissolution effects, effectively preventing PbI2 aggregation and passivating the resulting QDs. The resulting composite exhibits high-quality, narrow line width photoluminescence at room temperature, alongside remarkable stability under ambient conditions. This innovative approach offers a sustainable and efficient route for QD generation, underscoring the potential of MOF glass-based composites in optoelectronic applications.
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Jan 2026
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I15-1-X-ray Pair Distribution Function (XPDF)
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Chumei
Ye
,
Lauren N.
Mchugh
,
Pierre
Florian
,
Ruohan
Yu
,
Celia
Castillo-Blas
,
Celia
Chen
,
Arad
Lang
,
Yuhang
Dai
,
Jingwei
Hou
,
David A.
Keen
,
Sian E.
Dutton
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[35405]
Open Access
Abstract: Hybrid organic-inorganic perovskites (HOIPs) have garnered significant attention for their crystalline properties, yet recent findings reveal that they can also form liquid and glassy phases, offering an alternative platform for understanding non-crystalline materials. In this study, we present a detailed investigation into the structural dynamics of the melting and glass formation process of a two-dimensional (2D) HOIP, (S−(−)−1-(1−naphthyl)ethylammonium)2PbBr4. Compared to its crystalline counterpart, the glass exhibits superior mechanical properties, including higher Young’s modulus and hardness. Our structural studies reveal that the liquid and glass formed from the 2D HOIP exhibit network-forming behaviour, featuring limited short-range order within individual octahedra, partial retention of metal-halide-metal connectivity between neighbouring octahedra, and residual structural correlations mediated by organic cations. We then combine in situ variable-temperature X-ray total scattering experiments, terahertz far-infrared absorption spectroscopy and solid-state nuclear magnetic resonance techniques to study the melting mechanism and the nature of the HOIP liquid obtained. Our results deepen the understanding of the structural evolution and property relationships in HOIP glasses, providing a foundation for their potential applications in advanced phase-change material technologies.
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Aug 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Shichun
Li
,
Chao
Ma
,
Jingwei
Hou
,
Shuwen
Yu
,
Aibing
Chen
,
Juan
Du
,
Philip A.
Chater
,
Dean S.
Keeble
,
Zhihua
Qiao
,
Chongli
Zhong
,
David A.
Keen
,
Yu
Liu
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[20038]
Open Access
Abstract: Crystalline metal-organic frameworks (MOFs) exhibit enormous potential application in gas separation, thanks to their highly porous structures and precise pore size distributions. Nevertheless, the inherent limitations in mechanical stability of crystalline MOFs cause challenges in processing MOF powders into bulky structures, particularly for membrane filtrations. Melt-quenched MOF glasses boast excellent processability due to liquid-like properties. However, the melting process diminishes the inherent porosity, leading to reduced gas adsorption capacities and lower gas diffusion coefficients. In this work, we demonstrated that enhancing the porosity of MOF glasses is achievable through topological engineering on the crystalline precursors. Crystalline zeolitic imidazolate frameworks (ZIFs) with large 12-membered rings pores, including AFI and CAN topology, were synthesized by using both structure-directing agents and mixed organic ligands. The large pores are partially preserved in the melt-quenched glass as evidenced by high-pressure CO2 absorption at 3000 kPa. The agAFI-[Zn(Im)1.68(bIm)0.32] glass was then fabricated into self-supported membranes, which shows high gas separation performance, for example, CO2 permeance of 3.7 × 104 GPU with a CO2/N2 selectivity of 14.8.
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Feb 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Abstract: DUT-67 is a Zr-based metal–organic framework (MOF) that incorporates thiophene dicarboxylic acid linkers. In this study, we observed that DUT-67 underwent a striking structural order–disorder transition upon a dynamic heating process. We established a correlation between thermal responses and structural changes in DUT-67 during heating through both calorimetric analysis and structural characterization at various length scales. It was discovered that the chemical integrity of the DUT-67 linkers remained intact during heating. The morphology of DUT-67 was preserved after structural changes, while 50% of its porosity was retained, increasing the apparent density of the framework. The chemical changes caused by the heating were directly related to desolvation. The atomic pair distribution function analyses revealed that the structural disordering process occurred during heating. This was supported by a notable decrease in correlations between neighboring clusters, indicating a loss of structural order. The structural reordering in DUT-67 was found to involve multiple thermally induced phase transitions and then amorphization. The amorphous form of DUT-67 preserved both the high porosity and the functionality observed in its original crystalline state. This study implies that it is possible to find inherently unstable MOF structures for order–disorder engineering for creating new functionalities.
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Aug 2024
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E02-JEM ARM 300CF
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Jingwei
Hou
,
Peng
Chen
,
Atul
Shukla
,
Andraž
Krajnc
,
Tiesheng
Wang
,
Xuemei
Li
,
Rana
Doasa
,
Luiz H. G.
Tizei
,
Bun
Chan
,
Duncan N.
Johnstone
,
Rijia
Lin
,
Tobias U.
Schülli
,
Isaac
Martens
,
Dominique
Appadoo
,
Mark
S'Ari
,
Zhiliang
Wang
,
Tong
Wei
,
Shih-Chun
Lo
,
Mingyuan
Lu
,
Shichun
Li
,
Ebinazar B.
Namdas
,
Gregor
Mali
,
Anthony K.
Cheetham
,
Sean M.
Collins
,
Vicki
Chen
,
Lianzhou
Wang
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[21980, 25140]
Abstract: Lead halide perovskite (LHP) semiconductors show exceptional optoelectronic properties. Barriers for their applications, however, lie in their polymorphism, instability to polar solvents, phase segregation, and susceptibility to the leaching of lead ions. We report a family of scalable composites fabricated through liquid-phase sintering of LHPs and metal-organic framework glasses. The glass acts as a matrix for LHPs, effectively stabilizing nonequilibrium perovskite phases through interfacial interactions. These interactions also passivate LHP surface defects and impart bright, narrow-band photoluminescence with a wide gamut for creating white light-emitting diodes (LEDs). The processable composites show high stability against immersion in water and organic solvents as well as exposure to heat, light, air, and ambient humidity. These properties, together with their lead self-sequestration capability, can enable breakthrough applications for LHPs.
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Oct 2021
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I15-1-X-ray Pair Distribution Function (XPDF)
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Jingwei
Hou
,
María Laura
Ríos Gómez
,
Andraž
Krajnc
,
Aoife
Mccaul
,
Shichun
Li
,
Alice M.
Bumstead
,
Adam F.
Sapnik
,
Zeyu
Deng
,
Rijia
Lin
,
Philip A.
Chater
,
Dean S.
Keeble
,
David A.
Keen
,
Dominique
Appadoo
,
Bun
Chan
,
Vicki
Chen
,
Gregor
Mali
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[20038]
Abstract: The synthesis of four novel crystalline zeolitic imidazolate framework (ZIF) structures using a mixed-ligand approach is reported. The inclusion of both imidazolate and halogenated benzimidazolate-derived linkers leads to glass-forming behavior by all four structures. Melting temperatures are observed to depend on both electronic and steric effects. Solid-state NMR and terahertz (THz)/Far-IR demonstrate the presence of a Zn-F bond for fluorinated ZIF glasses. In situ THz/Far-IR spectroscopic techniques reveal the dynamic structural properties of crystal, glass and liquid phases of the halogenated ZIFs, linking the melting behavior of ZIFs to the propensity of the ZnN4 tetrahedra to undergo thermally-induced deformation. The inclusion of halogenated ligands within MOF-glasses improves their gas uptake properties.
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Jan 2020
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E02-JEM ARM 300CF
I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[20038, 20195]
Open Access
Abstract: Metal-organic framework crystal-glass composites (MOF-CGCs) are materials in which a crystalline MOF is dispersed within a MOF glass. In this work, we explore the room temperature stabilization of the open-pore form of MIL-53(Al), usually observed at high-temperature, which occurs upon encapsulation within a ZIF-62(Zn) MOF glass matrix. A series of MOF-CGCs containing different loadings of MIL-53(Al) were synthesized and characterized using X-ray diffraction and nuclear magnetic resonance spectroscopy. An upper limit of MIL-53(Al) that can be stabilized in the composite was determined for the first time. The nanostructure of the composites was probed using pair distribution function analysis and scanning transmission electron microscopy. Notably, the distribution and integrity of the crystalline compo-nent in a sample series was determined, and these findings related to the MOF-CGC gas adsorption capacity in order to identify the optimal loading necessary for maximum CO2 sorption capacity.
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Sep 2019
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E02-JEM ARM 300CF
I15-1-X-ray Pair Distribution Function (XPDF)
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Jingwei
Hou
,
Christopher W.
Ashling
,
Sean M.
Collins
,
Andraž
Krajnc
,
Chao
Zhou
,
Louis
Longley
,
Duncan N.
Johnstone
,
Philip
Chater
,
Shichun
Li
,
Marie-Vanessa
Coulet
,
Philip L.
Llewellyn
,
François-Xavier
Coudert
,
David
Keen
,
Paul A.
Midgley
,
Gregor
Mali
,
Vicki
Chen
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[171151, 19130, 16983]
Open Access
Abstract: The majority of research into metal-organic frameworks (MOFs) focuses on their crystalline nature. Recent research has revealed solid-liquid transitions within the family, which we use here to create a class of functional, stable and porous composite materials. Described herein is the design, synthesis, and characterisation of MOF crystal-glass composites, formed by dispersing crystalline MOFs within a MOF-glass matrix. The coordinative bonding and chemical structure of a MIL-53 crystalline phase are preserved within the ZIF-62 glass matrix. Whilst separated phases, the interfacial interactions between the closely contacted microdomains improve the mechanical properties of the composite glass. More significantly, the high temperature open pore phase of MIL-53, which spontaneously transforms to a narrow pore upon cooling in the presence of water, is stabilised at room temperature in the crystal-glass composite. This leads to a significant improvement of CO2 adsorption capacity.
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Jun 2019
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I22-Small angle scattering & Diffraction
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Louis
Longley
,
Sean M.
Collins
,
Shichun
Li
,
Glen J.
Smales
,
Ilknur
Erucar
,
Ang
Qiao
,
Jingwei
Hou
,
Cara M.
Doherty
,
Aaron W.
Thornton
,
Anita J.
Hill
,
Xiao
Yu
,
Nicholas J.
Terrill
,
Andrew J.
Smith
,
Seth M.
Cohen
,
Paul A.
Midgley
,
David A.
Keen
,
Shane G.
Telfer
,
Thomas
Bennett
Diamond Proposal Number(s):
[18236]
Open Access
Abstract: Recent demonstrations of melting in the metal–organic framework (MOF) family have created interest in the interfacial domain between inorganic glasses and amorphous organic polymers. The chemical and physical behaviour of porous hybrid liquids and glasses is of particular interest, though opportunities are limited by the inaccessible melting temperatures of many MOFs. Here, we show that the processing technique of flux melting, ‘borrowed’ from the inorganic domain, may be applied in order to melt ZIF-8, a material which does not possess an accessible liquid state in the pure form. Effectively, we employ the high-temperature liquid state of one MOF as a solvent for a secondary, non-melting MOF component. Differential scanning calorimetry, small- and wide-angle X-ray scattering, electron microscopy and X-ray total scattering techniques are used to show the flux melting of the crystalline component within the liquid. Gas adsorption and positron annihilation lifetime spectroscopy measurements show that this results in enhanced, accessible porosity to a range of guest molecules in the resultant flux melted MOF glass.
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Feb 2019
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