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1.
Cell ; 182(1): 127-144.e23, 2020 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-32502394

RESUMEN

Before zygotic genome activation (ZGA), the quiescent genome undergoes reprogramming to transition into the transcriptionally active state. However, the mechanisms underlying euchromatin establishment during early embryogenesis remain poorly understood. Here, we show that histone H4 lysine 16 acetylation (H4K16ac) is maintained from oocytes to fertilized embryos in Drosophila and mammals. H4K16ac forms large domains that control nucleosome accessibility of promoters prior to ZGA in flies. Maternal depletion of MOF acetyltransferase leading to H4K16ac loss causes aberrant RNA Pol II recruitment, compromises the 3D organization of the active genomic compartments during ZGA, and causes downregulation of post-zygotically expressed genes. Germline depletion of histone deacetylases revealed that other acetyl marks cannot compensate for H4K16ac loss in the oocyte. Moreover, zygotic re-expression of MOF was neither able to restore embryonic viability nor onset of X chromosome dosage compensation. Thus, maternal H4K16ac provides an instructive function to the offspring, priming future gene activation.


Asunto(s)
Histonas/metabolismo , Lisina/metabolismo , Activación Transcripcional/genética , Acetilación , Animales , Secuencia de Bases , Segregación Cromosómica/genética , Secuencia Conservada , Compensación de Dosificación (Genética) , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriología , Drosophila melanogaster/genética , Embrión no Mamífero/metabolismo , Evolución Molecular , Femenino , Genoma , Histona Acetiltransferasas/genética , Histona Acetiltransferasas/metabolismo , Masculino , Mamíferos/genética , Ratones , Mutación/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucleosomas/metabolismo , Oocitos/metabolismo , Regiones Promotoras Genéticas , ARN Polimerasa II/metabolismo , Cromosoma X/metabolismo , Cigoto/metabolismo
2.
Cell ; 167(3): 722-738.e23, 2016 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-27768893

RESUMEN

A functional crosstalk between epigenetic regulators and metabolic control could provide a mechanism to adapt cellular responses to environmental cues. We report that the well-known nuclear MYST family acetyl transferase MOF and a subset of its non-specific lethal complex partners reside in mitochondria. MOF regulates oxidative phosphorylation by controlling expression of respiratory genes from both nuclear and mtDNA in aerobically respiring cells. MOF binds mtDNA, and this binding is dependent on KANSL3. The mitochondrial pool of MOF, but not a catalytically deficient mutant, rescues respiratory and mtDNA transcriptional defects triggered by the absence of MOF. Mof conditional knockout has catastrophic consequences for tissues with high-energy consumption, triggering hypertrophic cardiomyopathy and cardiac failure in murine hearts; cardiomyocytes show severe mitochondrial degeneration and deregulation of mitochondrial nutrient metabolism and oxidative phosphorylation pathways. Thus, MOF is a dual-transcriptional regulator of nuclear and mitochondrial genomes connecting epigenetics and metabolism.


Asunto(s)
Metabolismo Energético/genética , Epigénesis Genética , Histona Acetiltransferasas/metabolismo , Mitocondrias Musculares/enzimología , Factores de Transcripción/metabolismo , Transcripción Genética , Animales , Cardiomiopatía Hipertrófica/genética , Respiración de la Célula/genética , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , Células HeLa , Insuficiencia Cardíaca/genética , Histona Acetiltransferasas/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular , Ratones , Ratones Noqueados , Mitocondrias Cardíacas/enzimología , Mitocondrias Cardíacas/genética , Mitocondrias Musculares/genética , Miocitos Cardíacos/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosforilación Oxidativa , Factores de Transcripción/genética
3.
Proc Natl Acad Sci U S A ; 121(6): e2312959121, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38300865

RESUMEN

The incorporation of multiple metal ions in metal-organic frameworks (MOFs) through one-pot synthesis can induce unique properties originating from specific atomic-scale spatial apportionment, but the extraction of this crucial information poses challenges. Herein, nondestructive solid-state NMR spectroscopy was used to discern the atomic-scale metal apportionment in a series of bulk Mg1-xCox-MOF-74 samples via identification and quantification of eight distinct arrangements of Mg/Co ions labeled with a 13C-carboxylate, relative to Co content. Due to the structural characteristics of metal-oxygen chains, the number of metal permutations is infinite for Mg1-xCox-MOF-74, making the resolution of atomic-scale metal apportionment particularly challenging. The results were then employed in density functional theory calculations to unravel the molecular mechanism underlying the macroscopic adsorption properties of several industrially significant gases. It is found that the incorporation of weak adsorption sites (Mg2+ for CO and Co2+ for CO2 adsorption) into the MOF structure counterintuitively boosts the gas adsorption energy on strong sites (Co2+ for CO and Mg2+ for CO2 adsorption). Such effect is significant even for Co2+ remote from Mg2+ in the metal-oxygen chain, resulting in a greater enhancement of CO adsorption across a broad composition range, while the enhancement of CO2 adsorption is restricted to Mg2+ with adjacent Co2+. Dynamic breakthrough measurements unambiguously verified the trend in gas adsorption as a function of metal composition. This research thus illuminates the interplay between atomic-scale structures and macroscopic gas adsorption properties in mixed-metal MOFs and derived materials, paving the way for developing superior functional materials.

4.
Proc Natl Acad Sci U S A ; 120(3): e2207080119, 2023 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-36623198

RESUMEN

The electrochemical conversion of waste nitrate (NO3-) to valuable ammonia (NH3) is an economical and environmentally friendly technology for sustainable NH3 production. It is beneficial for environmental nitrogen pollution management and is also an appealing alternative to the current Haber-Bosch process for NH3 production. However, owing to the competing hydrogen evolution reaction, it is necessary to design highly efficient and stable electrocatalysts with high selectivity. Herein, we report a rational design of Fe nanoparticles wrapped in N-doped carbon (Fe@N10-C) as a high NH3 selective and efficient electrocatalyst using a metal-organic framework precursor. We constructed a catalyst with new active sites by doping with nitrogen, which activated neighboring carbon atoms and enhanced metal-to-carbon electron transfer, resulting in high catalytic activity. These doped N sites play a key role in the NO3- electroreduction. As a result, the Fe@N10-C nanoparticles with optimal doping of N demonstrated remarkable performance, with a record-high NO3- removal capacity of 125.8 ± 0.5 mg N gcat-1 h-1 and nearly 100 % (99.7 ± 0.1%) selectivity. The catalyst also delivers an impressive NH3 production rate of 2647.7 µg h-1 cm-2 and high faradaic efficiency of 91.8 ± 0.1%. This work provides a new route for N-doped carbon-iron catalysis application and paves the way for addressing energy and environmental issues.

5.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35101982

RESUMEN

Ammonia (NH3) is an ideal carbon-free power source in the future sustainable hydrogen economy for growing energy demand. The electrochemical nitrate reduction reaction (NO3-RR) is a promising approach for nitrate removal and NH3 production at ambient conditions, but efficient electrocatalysts are lacking. Here, we present a metal-organic framework (MOF)-derived cobalt-doped Fe@Fe2O3 (Co-Fe@Fe2O3) NO3-RR catalyst for electrochemical energy production. This catalyst has a nitrate removal capacity of 100.8 mg N gcat-1 h-1 and an ammonium selectivity of 99.0 ± 0.1%, which was the highest among all reported research. In addition, NH3 was produced at a rate of 1,505.9 µg h-1 cm-2, and the maximum faradaic efficiency was 85.2 ± 0.6%. Experimental and computational results reveal that the high performance of Co-Fe@Fe2O3 results from cobalt doping, which tunes the Fe d-band center, enabling the adsorption energies for intermediates to be modulated and suppressing hydrogen production. Thus, this study provides a strategy in the design of electrocatalysts in electrochemical nitrate reduction.

6.
Nano Lett ; 24(32): 9906-9915, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39087644

RESUMEN

Rectifying the aberrant microenvironment of a disease through maintenance of redox homeostasis has emerged as a promising perspective with significant therapeutic potential for Alzheimer's disease (AD). Herein, we design and construct a novel nanozyme-boosted MOF-CRISPR platform (CMOPKP), which can maintain redox homeostasis and rescue the impaired microenvironment of AD. By modifying the targeted peptides KLVFFAED, CMOPKP can traverse the blood-brain barrier and deliver the CRISPR activation system for precise activation of the Nrf2 signaling pathway and downstream redox proteins in regions characterized by oxidative stress, thereby reinstating neuronal antioxidant capacity and preserving redox homeostasis. Furthermore, cerium dioxide possessing catalase enzyme-like activity can synergistically alleviate oxidative stress. Further in vivo studies demonstrate that CMOPKP can effectively alleviate cognitive impairment in 3xTg-AD mouse models. Therefore, our design presents an effective way for regulating redox homeostasis in AD, which shows promise as a therapeutic strategy for mitigating oxidative stress in AD.


Asunto(s)
Enfermedad de Alzheimer , Estrés Oxidativo , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genética , Animales , Ratones , Estrés Oxidativo/efectos de los fármacos , Humanos , Factor 2 Relacionado con NF-E2/metabolismo , Estructuras Metalorgánicas/química , Modelos Animales de Enfermedad , Sistemas CRISPR-Cas/genética , Cerio/química , Cerio/uso terapéutico , Cerio/farmacología , Barrera Hematoencefálica/metabolismo , Oxidación-Reducción , Antioxidantes/química , Antioxidantes/farmacología , Antioxidantes/uso terapéutico
7.
J Comput Chem ; 45(25): 2119-2127, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-38757907

RESUMEN

Bandgap is a key property that determines electrical and optical properties in materials. Modulating the bandgap thus is critical in developing novel materials particularly semiconductors with improved features. This study examines the bandgap, highest occupied molecular orbital (HOMO), and lowest unoccupied molecular orbital (LUMO) energy level trends in a metal organic framework, metal-organic framework 5 (MOF-5), as a function of Hammett substituent effect (with the constant σm in the meta-position of the benzene ring) and solvent dielectric effect (with the constant ε). Specifically, experimental design and response surface methodologies helped to assess the significance of trends and correlations between these molecular properties with σm and ε. While the HOMO and LUMO decrease with increasing σm, the LUMO exhibits greater sensitivity to the substituent's electron withdrawing capability. The relative difference in these trends helps to explain why the bandgap tends to decrease with increasing σm.

8.
J Comput Chem ; 45(17): 1515-1524, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38485224

RESUMEN

This study employs grand canonical Monte Carlo (GCMC) simulations to investigate the impact of functional group modifications (CH3, OH, NH2, and OLi) on the adsorption performance of CH4/N2 on Ni-MOF-74. The results revealed that functional group modifications significantly increased the adsorption capacity of Ni-MOF-74 for both CH4 and N2. The packed methyl groups in CH3-Ni-MOF-74 create an environment conducive to CH4, leading to the highest CH4 adsorption capacity. The electrostatic potential distribution indicates that the strong electron-donating effect introduced by the alkali metal Li results in the highest electrostatic potential gradient in Li-O-Ni-MOF-74, leading to the strongest adsorption of N2, this is unfavorable for CH4/N2 separation. At 1500 kPa the selectivity order of adsorbents for mixed gases was as follows: CH3-Ni-MOF-74 > NH2-Ni-MOF-74 > OH-Ni-MOF-74 > Ni-MOF-74 > Li-O-Ni-MOF-74. This study highlights that CH3-Ni-MOF-74 possesses optimal CH4 selectivity and adsorption performance. Given the current lack of research on functionalized MOF-74 for the separation of CH4 and N2, the findings of this study will serve as a theoretical guide and provide references for the applications of CH4 adsorption and CH4/N2 separation.

9.
Small ; : e2401587, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38855999

RESUMEN

Heterostructured materials commonly consist of bifunctions due to the different ingredients. For host material in the sulfur cathode of lithium-sulfur (Li-S) batteries, the chemical adsorption and catalytic activity for lithium polysulfides (LiPS) are important. This work obtains a Ni5P2-Ni nanoparticle (Ni5P2-NiNPs) heterostructure through a confined self-reduction method followed by an in situ phosphorization process using Al/Ni-MOF as precursors. The Ni5P2-Ni heterostructure not only has strong chemical adsorption, but also can effectively catalyze LiPS conversion. Furthermore, the synthetic route can keep Ni5P2-NiNPs inside of the nanocomposites, which have structural stability, high conductivity, and efficient adsorption/catalysis in LiPS conversion. These advantages make the assembled Li-S battery deliver a reversible specific capacity of 619.7 mAh g- 1 at 0.5 C after 200 cycles. The in situ ultraviolet-visible technique proves the catalytic effect of Ni5P2-Ni heterostructure on LiPS conversion during the discharge process.

10.
Small ; 20(26): e2310970, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38243848

RESUMEN

Hypergolicity is a highly desired characteristic for hybrid rocket engine-based fuels because it eliminates the need for a separate ignition system. Introducing hypergolic additives into conventional fuels through physical mixing is a feasible approach, but achieving highly reliable hypergolic ignition and energy release remains a major challenge. Here, the construction of core-shell Al@metal organic framework (MOF) heterostructures is reported as high-performance solid hypergolic propellants. Upon contact with the liquid oxidizer the uniformly distributed hypergolic MOF (Ag-MOF) shell can induce the ignition of hypergolic-inert fuel Al, resulting in Al combustion. Such a synthetic strategy is demonstrated to be favorable in hotspot generation and heat transfer relative to a simple physical mixture of Al/Ag-MOF, thus producing shorter ignition delay times and more efficient combustion. Thermal reactivity study indicated that the functionalization of the Ag-MOF shell changes the energy release process of the inner Al, which is accompanied by a thermite reaction. The synergistic effect of implantation of hypergolic MOF and high energy Al contributes to high specific impulses of 230-270 s over a wide range of oxidizer-to-fuel ratios.

11.
Small ; 20(25): e2306543, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38196152

RESUMEN

The fabrication of flexible composites by integrating metal-organic frameworks (MOFs) with flexible substrates is a critical strategy for developing advanced materials with excellent feasibility and processability. These flexible MOF-based composites play a particularly important role in the separation and purification processes. However, several drawbacks remain challenge to overcome such as long processing time, high-cost, complicated processes, or harsh reaction conditions. In this paper, a convenient and efficient method is reported for fabricating MOF/fiber composites using a simple drop-and-drain (D&D) process. By exploiting the electrostatic interactions between the positively charged MOF particles and negatively charged fiber-based flexible substrates, a uniform coating of MOF on flexible fibers are achieved. This is accomplished by allowing the MOF ink to drop and drain through a substrate using a custom-made Teflon cell. Additionally, the D&D method enables the production of multiple layers of composites in a single-step process. UiO-66 and ZIF-8 submicroparticles and various substrates such as cotton-pad, cotton-fabric, nylon-fabric, PET-fabric, and filter-paper are employed to create flexible MOF/fiber composites. These composites demonstrate outstanding capacities for capturing negatively charged organic dyes, including methyl orange and indigo carmine. Furthermore, the MOF/fiber composites can be reused for dye capture after a simple washing process.

12.
Small ; 20(32): e2310348, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38660830

RESUMEN

Due to their facile tunability, metal-organic frameworks (MOFs) are employed as precursors and templates to construct advanced functional materials with unique and desired chemical, physical, mechanical, and morphological properties. By tuning MOF precursor composition and manipulating conversion processes, various MOF-derived materials commonly known as MOF derivatives can be constructed. The possibility of controlled and predictable properties makes MOF derivatives a preferred choice for numerous advanced technological applications. The innovative synthetic designs besides the plethora of interdisciplinary characterization approaches applicable to MOF derivatives provide the opportunity to perform a myriad of experiments to explore the performance and offer key insight to develop the next generation of advanced materials. Though there are many published works of literature describing various synthesis and characterization techniques of MOF derivatives, it is still not clear how the synthesis mechanism works and what are the best techniques to characterize these materials to probe their properties accurately. In this review, the recent development in synthesis techniques and mechanisms for a variety of MOF derivates such as MOF-derived metal oxides, porous carbon, composites/hybrids, and sulfides is summarized. Furthermore, the details of characterization techniques and fundamental working principles are summarized to probe the structural, mechanical, physiochemical, electrochemical, and electronic properties of MOF and MOF derivatives. The future trends and some remaining challenges in the synthesis and characterization of MOF derivatives are also discussed.

13.
Small ; 20(23): e2308897, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38150665

RESUMEN

MXene is widely used in the construction of optoelectronic interfaces due to its excellent properties. However, the hydrophilicity and metastable surface of MXene lead to its oxidation behavior, resulting in the degradation of its various properties, which seriously limits its practical application. In this work, a 2D metal-organic framework (2D MOF) with matching 2D morphology, excellent stability performance, and outstanding optoelectronic performance is grown in situ on the MXene surface through heterojunction engineering to suppress the direct contact between reactive molecules and the inner layer material without affecting the original advantages of MXene. The photoelectric dual gain MXene@MOF heterojunction is confirmed. As a photoelectric material, its properties are highly suitable for the demand of interface sensitization layer materials of surface plasmon resonance (SPR). Therefore, using SPR as a platform for the application of this interface material, the performance of MXene@MOF and its potential mechanism to enhance SPR are analyzed in depth using experiments combined with simulation calculations (FDTD/DFT). Finally, the MXene@MOF/peptides-SPR sensor is constructed for rapid and sensitive detection of the cancer marker exosomes to explore its potential in practical applications. This work offers a forward-looking strategy for the design of interface materials with excellent photoelectric performance.

14.
Small ; 20(20): e2309119, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38126651

RESUMEN

Carbon neutrality is an important goal for humanity . As an eco-friendly technology, electrocatalytic clean energy conversion technology has emerged in the 21st century. Currently, metal-organic framework (MOF)-based electrocatalysis, including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), hydrogen oxidation reaction (HOR), carbon dioxide reduction reaction (CO2RR), nitrogen reduction reaction (NRR), are the mainstream energy catalytic reactions, which are driven by electrocatalysis. In this paper, the current advanced characterizations for the analyses of MOF-based electrocatalytic energy reactions have been described in details, such as density function theory (DFT), machine learning, operando/in situ characterization, which provide in-depth analyses of the reaction mechanisms related to the above reactions reported in the past years. The practical applications that have been developed for some of the responses that are of application values, such as fuel cells, metal-air batteries, and water splitting have also been demonstrated. This paper aims to maximize the potential of MOF-based electrocatalysts in the field of energy catalysis, and to shed light on the development of current intense energy situations.

15.
Small ; 20(18): e2309469, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38174621

RESUMEN

Property optimization through orientation control of metal-organic framework (MOF) crystals that exhibit anisotropic crystal structures continues to garner tremendous interest. Herein, an electric field is utilized to post-synthetically control the orientation of conductive layered Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) crystals dispersed in an electronically insulating poly(ethylene glycol) diacrylate (PEGDA) oligomer matrix. Optical and electrical measurements are performed to investigate the impact of the electric field on the alignment of Cu3(HHTP)2 crystals and the formation of aggregated microstructures, which leads to an ≈5000-fold increase in the conductivity of the composite. Notably, the composite thin-films containing aligned Cu3(HHTP)2 crystals exhibit significant conductivity of ≈10-3 S cm-1 despite the low concentration (≈1 wt.%) of conductive Cu3(HHTP)2. The use of an electric field to align Cu3(HHTP)2 crystals can rapidly generate various desired patterns that exhibit on-demand tunable collective charge transport anisotropy. The findings provide valuable insights toward the manipulation and utilization of conductive MOFs with anisotropic crystal structures for various applications such as adhesive electrical interconnects and microelectronics.

16.
Small ; 20(27): e2306616, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38342672

RESUMEN

Metal-organic frameworks (MOFs) are crystalline porous materials with a long-range ordered structure and excellent specific surface area and have found a wide range of applications in diverse fields, such as catalysis, energy storage, sensing, and biomedicine. However, their poor electrical conductivity and chemical stability, low capacity, and weak adhesion to substrates have greatly limited their performance. Doping has emerged as a unique strategy to mitigate the issues. In this review, the concept, classification, and characterization methods of doped MOFs are first introduced, and recent progress in the synthesis and applications of doped MOFs, as well as the rapid advancements and applications of first-principles calculations based on the density functional theory (DFT) in unraveling the mechanistic origin of the enhanced performance are summarized. Finally, a perspective is included to highlight the key challenges in doping MOF materials and an outlook is provided on future research directions.

17.
Small ; 20(27): e2307828, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38368249

RESUMEN

In recent years, there has been considerable focus on the development of charge transfer (CT) complex formation as a means to modify the band gaps of organic materials. In particular, CT complexes alternate layers of aromatic molecules with donor (D) and acceptor (A) properties to provide inherent electrical conductivity. In particular, the synthetic porous frameworks as attractive D-A components have been extensively studied in recent years in comparison to existing D-A materials. Therefore, in this work, the synthetic porous frameworks are classified into conjugated microporous polymers (CMPs), covalent organic frameworks (COFs), and metal-organic frameworks (MOFs) and compare high-quality materials for CT in semiconductors. This work updates the overview of the above porous frameworks for CT, starting with their early history regarding their semiconductor applications, and lists CT concepts and selected key developments in their CT complexes and CT composites. In addition, the network formation methods and their functionalization are discussed to provide access to a variety of potential applications. Furthermore, several theoretical investigations, efficiency improvement techniques, and a discussion of the electrical conductivity of the porous frameworks are also highlighted. Finally, a perspective of synthetic porous framework studies on CT performance is provided along with some comparisons.

18.
Small ; 20(32): e2309127, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38554016

RESUMEN

Conventional separation technologies for valuable commodities require substantial energy, accounting for 10%-15% of global consumption. Mixed-matrix membranes (MMMs) offer a promising solution by combining processable polymers with selective inorganic fillers. Here, the potential of using ordered microporous structured materials is demonstrated as MMM fillers. The use of ordered macroporous ZIF-67 in combination with the well-known 6FDA-DAM polymer leads to superior performance in the important separation of propylene from propane. The enhanced performance can be rationalized with the help of advanced microscopy, which demonstrates that the polymer is able to penetrate the macroporous network around which the MOF (Metal-Organic Framework) is synthesized, resulting in a much better interphase between the two components and the homogeneous distribution of the filler, even at high loadings.

19.
Small ; 20(34): e2400978, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38593307

RESUMEN

Lead (Pb) poisoning and CO2-induced global warming represent two exemplary environmental and energy issues threatening humanity. Various biomass-derived materials are reported to take up Pb and convert CO2 electrochemically into low-valent carbon species, but these works address the problems separately rather than settle the issues simultaneously. In this work, cheap, natural ellagic acid (EA) extracted from common plants is adopted to assemble a stable metal-organic framework (MOF), EA-Pb, by effective capture of Pb2+ ions in an aqueous medium (removal rate close to 99%). EA-Pb represents the first structurally well-defined Pb-based MOF showing selective electrocatalytic CO2-to-HCOO- conversion with Faradaic efficiency (FE) of 95.37% at -1.08 V versus RHE. The catalytic mechanism is studied by 13CO2 labeling, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and theoretical calculation. The use of EA-Pb as an electrocatalyst for CO2 reduction represents a 2-in-1 solution of converting detrimental wastes (Pb2+) as well as natural resources (EA) into wealth (electrocatalytic EA-Pb) for addressing the global warming issue.

20.
Small ; : e2404055, 2024 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-38970546

RESUMEN

Laccase is capable of catalyzing a vast array of reactions, but its low redox potential limits its potential applications. The use of photocatalytic materials offers a solution to this problem by converting absorbed visible light into electrons to facilitate enzyme catalysis. Herein, MIL-53(Fe) and NH2-MIL-53(Fe) serve as both light absorbers and enzyme immobilization carriers, and laccase is employed for solar-driven chemical conversion. Electron spin resonance spectroscopy results confirm that visible light irradiation causes rapid transfer of photogenerated electrons from MOF excitation to T1 Cu(II) of laccase, significantly increasing the degradation rate constant of tetracycline (TC) from 0.0062 to 0.0127 min-1. Conversely, there is only minimal or no electron transfer between MOF and laccase in the physical mixture state. Theoretical calculations demonstrate that the immobilization of laccase's active site and its covalent binding to the metal-organic framework surface augment the coupled system's activity, reducing the active site accessible from 27.8 to 18.1 Å. The constructed photo-enzyme coupled system successfully combines enzyme catalysis' selectivity with photocatalysis's high reactivity, providing a promising solution for solar energy use.

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