B18-Core EXAFS
|
Diamond Proposal Number(s):
[39179]
Open Access
Abstract: Developing photocatalysts that can efficiently utilize the full solar spectrum is a crucial step toward transforming sustainable energy solutions. Due to their light absorption limitations, most photo-responsive metal−organic frameworks (MOFs) are constrained to the ultraviolet (UV) and blue light regions. Expanding their absorp-tion to encompass the entire solar spectrum would unlock their full potential, greatly enhancing efficiency and applicability. Here, we report the design and synthesis of a series of highly stable boron-dipyrromethene (bodipy) based MOFs (BMOFs) by reacting dicar-boxyl-functionalized bodipy ligands with Zr-oxo clusters. Leveraging the acidity of the methyl groups on the bodipy backbone, we ex-panded the conjugation system through a solid-state condensation reaction with various aldehydes, achieving full-color absorption, thereby extending the band edge into the near-infrared (NIR) and infrared (IR) regions. These BMOFs demonstrated exceptional reac-tivity and recyclability in heterogeneous photocatalytic activities, including C−H bond activation of saturated aza-heterocycles and C−N bond cleavage of N,N-dimethylanilines to produce amides under visible light. Our findings highlight the transformative potential of BMOFs in photocatalysis, marking a significant leap forward in the design of advanced photocatalytic materials with tunable properties.
|
Apr 2025
|
|
|
|
Abstract: Metal–organic frameworks hold immense application potential, but their stability and environmental safety remain barriers to industrial translation. Embracing the ‘safe and sustainable by design’ framework would, however, set a transformative pathway to the development of robust, recyclable metal–organic frameworks, ensuring functionality, minimal ecological impact and alignment with circular economy and chemical sustainability goals.
|
Jan 2025
|
|
B18-Core EXAFS
I11-High Resolution Powder Diffraction
|
Xu
Chen
,
Dhruv
Menon
,
Xiaoliang
Wang
,
Meng
He
,
Mohammad Reza
Alizadeh Kiapi
,
Mehrdad
Asgari
,
Yuexi
Lyu
,
Xianhui
Tang
,
Luke L.
Keenan
,
William
Shepard
,
Lik H.
Wee
,
Sihai
Yang
,
Omar K.
Farha
,
David
Fairen-Jimenez
Diamond Proposal Number(s):
[32566, 34552]
Open Access
Abstract: Selective CO2 capture from industry is crucial for reducing emissions from fossil fuel combustion. Flexible metal-organic frameworks (MOFs) have shown promise for CO2 adsorption via differential binding and size-exclusion mechanisms. However, achieving precise pore-size control to selectively capture CO2, particularly in the presence of N2 and water, remains a challenge. Here, we demonstrate a strategy for frustrating framework flexibility in a MOF to create an optimal, confined pore environment that enhances selective CO2 recognition while maintaining high working capacity. We designed a flexible MOF, Cambridge University (CU)-4, by using a bulky cubane-derived ligand and In3+ ions that undergo dynamic breathing with a 2 Å contraction upon solvent exchange and removal. In situ synchrotron X-ray diffraction and molecular simulations reveal that the stable narrow-pore configuration creates a hydrogen-rich cavity that selectively binds CO2 via multiple hydrogen bonds. This physisorption-based CO2 recognition remains effective even at 80% humidity, making CU-4 promising for post-combustion carbon capture.
|
Jan 2025
|
|
B18-Core EXAFS
I11-High Resolution Powder Diffraction
|
Prathmesh
Bhadane
,
Dhruv
Menon
,
Prateek
Goyal
,
Mohammad Reza
Alizadeh Kiapi
,
Biraj
Kanta Satpathy
,
Arianna
Lanza
,
Iuliia
Mikulska
,
Rebecca
Scatena
,
Stefan
Michalik
,
Priya
Mahato
,
Mehrdad
Asgari
,
Xu
Chen
,
Swaroop
Chakraborty
,
Abhijit
Mishra
,
Iseult
Lynch
,
David
Fairen-Jimenez
,
Superb K.
Misra
Diamond Proposal Number(s):
[39677, 38403]
Abstract: Recycling and recovery of rare earth elements (REEs) from electronic wastes can accelerate efforts to mitigate the environmental burden associated with their excessive mining, while catering for their growing demand. Contemporary recovery strategies are yet to make an impact at an industrial scale due to low REE uptakes, complex mechanisms, and high regeneration energies, leading to an overall poor scalability. Here, we report a two-dimensional metal–organic framework (BNMG-1) featuring a dense arrangement of active adsorption sites for the high uptake of heavy and light REEs. BNMG-1 with a lateral dimension of ca. 350 nm and a thickness of 14 nm was synthesized via a facile one-pot reaction using a green solvent under room temperature and atmospheric pressure. The two-dimensional structure of BNMG-1 was resolved using three-dimensional electron diffraction and EXAFS analysis. Batch experiments showed BNMG-1 to have an adsorption capacity of 355.8 mg/g for Nd3+, 323.1 mg/g for Y3+, 331 mg/g for Dy3+, 329mg/g for Tb3+ and 333 mg/g for Eu3+, which is a near-benchmark performance for a non-functionalised MOF. The adsorption efficiency for Nd3+ reached 99 % by 6 h and 88 % by 48 h for Y3+. The adsorption efficiency did not get affected over a pH range of 3 to 6 and retained > 99 % of its adsorption capacity for up to 4 cycles. For application on real-life samples, CFL lamp waste and waste magnets were used as a reservoir of heavy (Yttrium) and light (Neodymium) REEs. BNMG-1 demonstrates an efficient recovery of 57 % for Neodymium from scrap magnets and 27 % for Yttrium from waste fluorescent lamps. This performance, which is maintained under acidic conditions and over multiple cycles, highlights the competitiveness of BNMG-1 for the economic large-scale recovery of REEs.
|
Dec 2024
|
|
B21-High Throughput SAXS
labSAXS-Offline SAXS and Sample Environment Development
|
Diamond Proposal Number(s):
[29568, 30717, 30473]
Open Access
Abstract: The instability and limited scalability of halide perovskites hinder their long-term viability in applications as X-ray detectors. Here, we introduce a sol-gel ship-in-bottle approach to produce a monolithic perovskite@metal-organic framework (MOF) composite, combining the properties of the individual building blocks and enhancing density, robustness, and stability. By tuning seed particles below 100 nm, we achieve highly crystalline, dense composites with up to 40% perovskite loading. Structural and optical characterization unveils perovskite nanocrystals forming within MOF mesopores, maximizing stability and preventing degradation, maintaining over 90% photoluminescence and structural integrity after weeks of exposure to humidity, heat, and solvents. Proposed as an innovative class of scintillator, these monolithic perovskite@MOFs attenuate X-rays efficiently and exhibit outstanding stability under high radiation doses equivalent to 110,000 typical chest X-rays, with a radioluminescence lifetime of 10 ns, outperforming commercial scintillators. This approach offers vast potential for developing high-performance, cost-effective, and stable devices for radiation detection and other optoelectronic applications.
|
Sep 2024
|
|
I11-High Resolution Powder Diffraction
|
A. J. R.
Thom
,
D. G.
Madden
,
R.
Bueno-Perez
,
A.n.
Al Shakhs
,
C. T.
Lennon
,
R. J.
Marshall
,
C. A.
Walshe
,
C.
Wilson
,
C. A.
Murray
,
S. P.
Thompson
,
G. F.
Turner
,
D.
Bara
,
S. A.
Moggach
,
D.
Fairen-Jimenez
,
R. S.
Forgan
Diamond Proposal Number(s):
[22028]
Open Access
Abstract: To achieve optimal performance in gas storage and delivery applications, metal–organic frameworks (MOFs) must combine high gravimetric and volumetric capacities. One potential route to balancing high pore volume with suitable crystal density is interpenetration, where identical nets sit within the void space of one another. Herein, we report an interpenetrated MIL-53 topology MOF, named GUF-1, where one-dimensional Sc(μ2-OH) chains are connected by 4,4′-(ethyne-1,2-diyl)dibenzoate linkers into a material that is an unusual example of an interpenetrated MOF with a rod-like secondary building unit. A combination of modulated self-assembly and grand canonical Monte Carlo simulations are used to optimise the porosity of GUF-1; H2 adsorption isotherms reveal a moderately high Qst for H2 of 7.6 kJ/mol and a working capacity of 41 g/L in a temperature–pressure swing system, which is comparable to benchmark MOFs. These results show that interpenetration is a potentially viable route to high-performance gas storage materials comprised of relatively simple building blocks.
|
Jun 2022
|
|
B18-Core EXAFS
|
Jamie W.
Gittins
,
Chloe J.
Balhatchet
,
Yuan
Chen
,
Cheng
Liu
,
David G.
Madden
,
Sylvia
Britto
,
Matthias J.
Golomb
,
Aron
Walsh
,
David
Fairen-Jimenez
,
Sian E.
Dutton
,
Alexander C.
Forse
Diamond Proposal Number(s):
[14239]
Open Access
Abstract: Two-dimensional electrically conductive metal–organic frameworks (MOFs) have emerged as promising model electrodes for use in electric double-layer capacitors (EDLCs). However, a number of fundamental questions about the behaviour of this class of materials in EDLCs remain unanswered, including the effect of the identity of the metal node and organic linker molecule on capacitive performance, and the limitations of current conductive MOFs in these devices relative to traditional activated carbon electrode materials. Herein, we address both these questions via a detailed study of the capacitive performance of the framework Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) with an acetonitrile-based electrolyte, finding a specific capacitance of 110–114 F g−1 at current densities of 0.04–0.05 A g−1 and a modest rate capability. By directly comparing its performance with the previously reported analogue, Ni3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene), we illustrate that capacitive performance is largely independent of the identity of the metal node and organic linker molecule in these nearly isostructural MOFs. Importantly, this result suggests that EDLC performance in general is uniquely defined by the 3D structure of the electrodes and the electrolyte, a significant finding not demonstrated using traditional electrode materials. Finally, we probe the limitations of Cu3(HHTP)2 in EDLCs, finding a limited stable double-layer voltage window of 1 V and only a modest capacitance retention of 81% over 30 000 cycles, both significantly lower than state-of-the-art porous carbons. These important insights will aid the design of future conductive MOFs with greater EDLC performances.
|
Jun 2021
|
|
I11-High Resolution Powder Diffraction
|
Open Access
Abstract: Stimuli-responsive behaviors of flexible metal–organic frameworks (MOFs) make these materials promising in a wide variety of applications such as gas separation, drug delivery, and molecular sensing. Considerable efforts have been made over the last decade to understand the structural changes of flexible MOFs in response to external stimuli. Uniform pore deformation has been used as the general description. However, recent advances in synthesizing MOFs with non-uniform porous structures, i.e. with multiple types of pores which vary in size, shape, and environment, challenge the adequacy of this description. Here, we demonstrate that the CO2-adsorption-stimulated structural change of a flexible MOF, ZIF-7, is induced by CO2 migration in its non-uniform porous structure rather than by the proactive opening of one type of its guest-hosting pores. Structural dynamics induced by guest migration in non-uniform porous structures is rare among the enormous number of MOFs discovered and detailed characterization is very limited in the literature. The concept presented in this work provides new insights into MOF flexibility.
|
Mar 2019
|
|
I19-Small Molecule Single Crystal Diffraction
|
Abstract: Many zeolitic imidazolate frameworks (ZIFs) are promising candidates for use in separation technologies. Comprising large cavities interconnected by small windows they can be used, at least in principle, as molecular sieves where molecules smaller than the window size are able to diffuse into the material while larger are rejected. However, “swing effect” or “gate opening” phenomena resulting in an enlargement of the windows have proven to be detrimental. Here, we present the first systematic experimental and computational study of the effect of chemical functionalisation of the imidazole linker on the framework dynamics. Using high-pressure (HP) single-crystal X-ray diffraction, density functional theory, and grand canonical Monte Carlo simulations, we show that in the isostructural ZIF-8, ZIF-90 and ZIF-65 functional groups of increasing polarity (-CH3,-CHO, -NO2) on the imidazole linkers provide control over the degree of rotation and thus the critical window diameter. On application of pressure, the substituted imidazolate rings rotate resulting in an increase in both pore volume and content. Our results show that the interplay between the guest molecules and the chemical function of the imidazole linker is essential for directing the swing effect in ZIF frameworks and therefore the adsorption performance.
|
Dec 2017
|
|
I11-High Resolution Powder Diffraction
I12-JEEP: Joint Engineering, Environmental and Processing
I15-Extreme Conditions
|
Matthew J.
Cliffe
,
Elizabeth
Castillo-Martinez
,
Yue
Wu
,
Jeongjae
Lee
,
Alexander C.
Forse
,
Francesca C. N.
Firth
,
Peyman Z.
Moghadam
,
David
Fairen-Jimenez
,
Michael W.
Gaultois
,
Joshua A.
Hill
,
Oxana V.
Magdysyuk
,
Ben
Slater
,
Andrew L.
Goodwin
,
Clare P.
Grey
Diamond Proposal Number(s):
[9940, 15118, 12554, 13681, 13843]
Open Access
Abstract: We report a hafnium containing MOF, hcp UiO-67(Hf), which is a defective layered analogue of the face-centered cubic fcu UiO-67(Hf). hcp UiO-67 accommodates its low- ered ligand:metal ratio compared to fcu UiO-67 through a new structural mechanism: the formation of a condensed ‘double cluster’, analogous to the condensation of coor- dination polyhedra in oxide frameworks. In oxide frameworks variable stoichiometry can lead to more complex defect structures, e.g. crystallographic shear planes or mod- ules with differing compositions, which can be the source of further chemical reactivity; likewise the layered hcp UiO-67 can react further to form two-dimensional nanosheets. Delamination of hcp UiO-67 occurs through the cleavage of strong hafnium-carboxylate bonds and is effected under mild conditions suggesting that defect ordered MOFs could be a productive route to porous two-dimensional materials.
|
Mar 2017
|
|
