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1.
Mol Cell ; 81(9): 1970-1987.e9, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-33725485

RESUMO

Depletion of architectural factors globally alters chromatin structure but only modestly affects gene expression. We revisit the structure-function relationship using the inactive X chromosome (Xi) as a model. We investigate cohesin imbalances by forcing its depletion or retention using degron-tagged RAD21 (cohesin subunit) or WAPL (cohesin release factor). Cohesin loss disrupts the Xi superstructure, unveiling superloops between escapee genes with minimal effect on gene repression. By contrast, forced cohesin retention markedly affects Xi superstructure, compromises spreading of Xist RNA-Polycomb complexes, and attenuates Xi silencing. Effects are greatest at distal chromosomal ends, where looping contacts with the Xist locus are weakened. Surprisingly, cohesin loss creates an Xi superloop, and cohesin retention creates Xi megadomains on the active X chromosome. Across the genome, a proper cohesin balance protects against aberrant inter-chromosomal interactions and tempers Polycomb-mediated repression. We conclude that a balance of cohesin eviction and retention regulates X inactivation and inter-chromosomal interactions across the genome.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Células-Tronco Embrionárias/metabolismo , Inativação Gênica , Proteínas do Grupo Polycomb/metabolismo , RNA Longo não Codificante/metabolismo , Inativação do Cromossomo X , Cromossomo X , Animais , Proteínas de Ciclo Celular/genética , Linhagem Celular , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Camundongos , Conformação de Ácido Nucleico , Proteínas do Grupo Polycomb/genética , Conformação Proteica , Proteínas/genética , Proteínas/metabolismo , RNA Longo não Codificante/genética , Relação Estrutura-Atividade , Coesinas
2.
Nano Lett ; 24(22): 6496-6505, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38787288

RESUMO

Asymmetric surface functionalization of complex nanoparticles to control their directional self-assembly remains a considerable challenge. Here, we demonstrated a conformal DNA design strategy for flexible remodeling of the surface of complex nanoparticles, taking Au nanobipyramids (AuNBPs) as a model. We sheathed one or both tips of AuNBPs into conformal DNA origami with an exceptionally accurate orientation control. Such asymmetrically and symmetrically distributed surface patches possess regioselective, sequence, and site-specific DNA binding capabilities. As a result, we realized a series of prototypical multicomponent "colloidal molecules" made of AuNBPs and Au nanospheres (AuNSs) with defined directionality and number of "bonding valence" as well as 1D and 3D hierarchical assemblies, e.g., inverse core-satellites of AuNBPs and AuNSs, side-by-side and tip-to-tip linear assemblies of AuNBPs, and 3D helical superstructures of AuNBPs with tunable twists. These findings inspire new opportunities for nanoparticle surface engineering and the high-order self-assembly of nanoarchitectures with higher complexity and broadened functionalities.


Assuntos
DNA , Ouro , Nanopartículas Metálicas , Propriedades de Superfície , Ouro/química , DNA/química , Nanopartículas Metálicas/química , Conformação de Ácido Nucleico
3.
Small ; 20(13): e2306154, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37967353

RESUMO

Hierarchical superstructures have novel shape-dependent properties, but well-defined anisotropic carbon superstructures with controllable size, shape, and building block dimensionality have rarely been accomplished thus far. Here, a hierarchical assembly technique is presented that uses spinodal decomposition (SD) to synthesize anisotropic oblate particles of mesoporous carbon superstructure (o-MCS) with nanorod arrays by integrating block-copolymer (BCP) self-assembly and polymer-polymer interface behaviors in binary blends. The interaction of major and minor phases in binary polymer blends leads to the formation of an anisotropic oblate particle, and the BCP-rich phase enables ordered packing and unidirectional alignment of carbon nanorods. Consequently, this approach enables precise control over particles' size, shape, and over the dimensionality of their components. Exploiting this functional superstructure, o-MCS are used as an anode material in potassium-ion batteries, and achieve a notable specific capacity of 156 mA h g-1 at a current density of 2 A g-1, and long-term stability for 3000 cycles. This work presents a significant advancement in the field of hierarchical superstructures, providing a promising strategy for the design and synthesis of anisotropic carbon materials with controlled properties, offering promising applications in energy storage and beyond.

4.
Small ; 20(32): e2400774, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38616778

RESUMO

Capacitive carbon cathodes deliver great potential for zinc-ion hybrid capacitors (ZHCs) due to their resource abundance and structural versatility. However, the dimension mismatch between the micropores of carbons and hydrated Zn2+ ions often results in unsatisfactory charge storage capability. Here well-arranged heterodiatomic carbon superstructures are reported with compatible pore dimensions for activating Zn2+ ions, initiated by the supramolecular self-assembly of 1,3,5-triazine-2,4,6-triamine and cyanuric acid via in-plane hydrogen-bonds and out-of-plane π-π interactions. Flower-shaped carbon superstructures expose more surface-active motifs, continuous charge-transport routes, and more importantly, well-developed pores. The primary subnanopores of 0.82 nm are size-exclusively accessible for solvated Zn2+ ions (0.86 nm) to maximize spatial charge storage, while rich mesopores (1-3 nm) allow for high-kinetics ion migration with a low activation energy. Such favorable superstructure cathodes contribute to all-round performance improvement for ZHCs, including high energy density (158 Wh kg-1), fast-charging ability (50 A g-1), and excellent cyclic lifespan (100 000 cycles). An anion-cation hybrid charge storage mechanism is elucidated for superstructure cathode, which entails alternate physical uptake of Zn2+/CF3SO3 - at electroactive pores and bipedal chemical binding of Zn2+ to electronegative carbonyl/pyridine motifs. This work expands the design landscape of carbon superstructures for advanced energy storage.

5.
Nano Lett ; 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37967165

RESUMO

The hierarchical self-assembly of colloidal particles facilitates the bottom-up manufacturing of metamaterials with synergistically integrated functionalities. Here, we define a modular assembly methodology that enables multinary co-assembly of nanoparticles in one-dimensional confined space. A series of isotropic and anisotropic nanocrystals such as plasmonic, metallic, visible, and near-infrared responsive nanoparticles as well as transition-metal phosphides can be selectively assembled within the single-walled Co(OH)2 nanotubes to achieve various increasingly sophisticated assembly systems, including unary, binary, ternary, and quaternary superstructures. Moreover, the selective assembly of distinct functional nanoparticles produces different integrated functional superstructures. This generalizable methodology provides predictable pathways to complex architectures with structural programming and customization that are otherwise inaccessible.

6.
Small ; 19(39): e2302475, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37231568

RESUMO

Developing an inexpensive bifunctional electrocatalyst for overall water splitting is critical for acquiring scalable green hydrogen and thereby realizing carbon neutralization. Herein, an "all-in-one" method is developed for the fabrication of highly N-doped binary FeCo-phosphides (N-FeCoP) with hierarchical superstructure, this delicately designed synthesis route allows the following merits for benefiting water splitting electrocatalysis in alkaline, including high N/defect-doping for mediating the surface property of the as-made N-FeCoP, binary Fe and Co components exhibiting strong coupling interaction, and 3D hierarchical superstructure for shortening diffusion length and thereby improving reaction kinetics. Electrochemical measurements reveal that the N-FeCoP sample exhibits very low overpotentials for initiating the hydrogen and oxygen evolution reactions. Remarkably, overall water splitting can be promoted on N-FeCoP using a commercial primary Zn-MnO2 battery. The developed synthesis strategy may potentially inspire the preparation of other N-doped metal-based nanostructures for broad electrocatalysis.

7.
Small ; : e2308739, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38054629

RESUMO

Building of metal-organic frameworks (MOFs) homogeneous hydrogels made by spontaneous crystallization remains a significant challenge. Inspired by anisotropically structured materials in nature, an oriented super-assembly strategy to construct micro-scale MOFs superstructure is reported, in which the strong intermolecular interactions between zirconium-oxygen (Zr─O) cluster and glutamic acid are utilized to drive the self-assembly of flexible nanoribbons into pumpkin-like microspheres. The confined effect between water-flexible building blocks and crosslinked hydrogen networks of superstructures achieved a mismatch transformation of MOFs powders into homogeneous hydrogels. Importantly, the elastic and rigid properties of hydrogels can be simply controlled by precise modulation of coordination and self-assembly for anisotropic superstructure. Experimental results and theoretical calculations demonstrates that MOFs anisotropic superstructure exhibits dynamic double networks with a superior water harvesting capacity (119.73 g g-1 ) accompanied with heavy metal removal (1331.67 mg g-1 ) and strong mechanical strength (Young's modulus of 0.3 GPa). The study highlights the unique possibility of tailoring MOFs superstructure with homogeneous hydrogel behavior for application in diverse fields.

8.
Small ; 19(15): e2207119, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36683222

RESUMO

Atomically precise nanoclusters (NCs) have recently emerged as ideal building blocks for constructing self-assembled multifunctional superstructures. The existing structures are based on various non-covalent interactions of the ligands on the NC surface, resulting in inter-NC interactions. Despite recent demonstrations on light-induced reversible self-assembly, long-range reversible self-assembly based on dynamic covalent chemistry on the NC surface has yet to be investigated. Here, it is shown that Au25 NCs containing thiolated umbelliferone (7-hydroxycoumarin) ligands allow [2+2] photocycloaddition reaction-induced self-assembly into colloidal-level toroids. The toroids upon further irradiation undergo inter-toroidal reaction resulting in macroscopic supertoroidal honey-comb frameworks. Systematic investigation using electron microscopy, atomic force microscopy (AFM), and electron tomography (ET) suggest that the NCs initially form spherical aggregates. The spherical structures further undergo fusion resulting in toroid formation. Finally, the toroids fuse into macroscopic honeycomb frameworks. As a proof-of-concept, a cross-photocycloaddition reaction between coumarin-tethered NCs and an anticancer drug (5-fluorouracil) is demonstrated as a model photo-controlled drug release system. The model system allows systematic loading and unloading of the drug during the assembly and disassembly under two different wavelengths. The results suggest that the dynamic covalent chemistry on the NC surface offers a facile route for hierarchical multifunctional frameworks and photocontrolled drug release.

9.
Small ; 19(22): e2300239, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36855782

RESUMO

The electrocatalytic nitrogen reduction reaction (NRR) to synthesize NH3 under ambient conditions is a promising alternative route to the conventional Haber-Bosch process, but it is still a great challenge to develop electrocatalysts' high Faraday efficiency and ammonia yield. Herein, a facile and efficient exfoliation strategy to synthesize ultrathin 2D boron and nitrogen co-doped porous carbon nanosheets (B/NC NS) via a metal-organic framework (MOF)-derived van der Waals superstructure, is reported. The results of experiments and theoretical calculations show that the doping of boron and nitrogen can modulate the electronic structure of the adjacent carbon atoms; which thus, promotes the competitive adsorption of nitrogen and reduces the energy required for ammonia synthesis. The B/NC NS exhibits excellent catalytic performance and stability in electrocatalytic NRR, with a yield rate of 153.4 µg·h-1 ·mg-1 cat and a Faraday efficiency of 33.1%, which is better than most of the reported NRR electrocatalysts. The ammonia yield of B/NC NS can maintain 92.7% of the initial NRR activity after 48 h stability test. The authors' controllable exfoliation strategy using MOF-derived van der Waals superstructure can provide a new insight for the synthesis of other 2D materials.

10.
Chem Rec ; 23(1): e202200180, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36149036

RESUMO

Scientists are often inspired by nature, where naturally occurring morphologies, such as those that resemble animals and plants, can be created in the lab. In this review, we have provided an overview on complex superstructures of animals, plants and some similar shapes from the natural world. We begin this review with a discussion about the formation of various animal-like shapes from small organic molecules and polymers, and then move onto plants and other selected shapes. Literature surveys reveal that most of the polymers studied tend to form micellar structures, with some exceptions. Nevertheless, small organic molecules tend to form not only micellar structures but also other animal shapes such as worms and caterpillars. These superstructures tend to have high surface areas and variable surface morphology, making them very useful material for applications in various field such as catalysis, solar cells, and biomedicine, amongst others.

11.
Angew Chem Int Ed Engl ; 62(39): e202309027, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37552154

RESUMO

The precise control over hierarchical self-assembly of superstructures relying on the elaboration of multiple noncovalent interactions between basic building blocks is both elusive and highly desirable. We herein report a terpyridine-based metallo-cage T with a tetrahedral motif and utilized it as an efficient building block for the controlled hierarchical self-assembly of superstructures in response to different halide ions. Initially, the hierarchical superstructure of metallo-cage T adopted a hexagonal close-packed structure. By adding Cl- /Br- or I- , drastically different hierarchical superstructures with highly-tight hexagonal packing or graphite-like packing arrangements, respectively, have been achieved. These unusual halide-ion-triggered hierarchical structural changes resulted in quite distinct intermolecular channels, which provided new insights into the mechanism of three-dimensional supramolecular aggregation and crystal growth based on macromolecular construction. In addition, the chiral induction of the metallo-cage T can be realized with the addition of chiral anions, which stereoselectively generated either PPPP- or MMMM-type enantiomers.

12.
Angew Chem Int Ed Engl ; 62(50): e202315136, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37902429

RESUMO

The helical twisting tendency of liquid crystals (LCs) is generally governed by the inherent configuration of the chiral emitter. Here, we introduce the multistage inversion of supramolecular chirality as well as circularly polarized luminescence (CPL) by manipulating the ratio of single enantiomeric emitters (R-PCP) to LC monomers (5CB). Increasing the content of R-PCP from 1 wt % to 3 wt % inverted the helix of LCs from left-handed to right-handed, accompanying a CPL sign changed from positive to negative. The biaxiality of chiral emitters, as well as the steric effect of chiral-chiral and chiral-achiral interaction, were identified as the reasons for helical sense inversion. Due to the strong helical twisting power, 4 wt % R-PCP drove the photonic band gap (PBG) of chiral LCs to match up with their emission range, leading to an inversion of the CPL again with a high dissymmetry factor (≈1.2). Directly adjusting the PBG using chiral emitters is seldom achieved in cholesteric LCs. On this basis, an achiral sensitizer PtTPBP was assembled into the helical superstructure. The generation of triplet-triplet annihilation-induced upconverted CPL from R-PCP and the downshifting CPL from PtTPBP with opposite rotation was achieved in a single chiral LC system by tuning the position of the PBG.

13.
Angew Chem Int Ed Engl ; 62(10): e202219025, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36646648

RESUMO

Intricate superstructures possess unusual structural features and promising applications. The preparation of superstructures with single-crystalline nature are conducive to understanding the structure-property relationship, however, remains an intriguing challenge. Herein we put forward a new hierarchical assembly strategy towards rational and precise construction of intricate single-crystal superstructures. Firstly, two unprecedented superclusters in Rubik's cube's form with a size of ≈2×2×2 nm3 are constructed by aggregation of eight {Pr4 Sb12 } oxohalide clusters as secondary building units (SBUs). Then, the Rubik's cubes further act as isolable tertiary building units (TBUs) to assemble diversified single-crystal superstructures. Importantly, intermediate assembly states are captured, which helps illustrate the evolution of TBU-based superstructures and thus provides a profound understanding of the assembly process of superstructures at the atomic level.

14.
Angew Chem Int Ed Engl ; 62(13): e202219136, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36695445

RESUMO

With fast (de)coordination kinetics, the smallest and the lightest proton stands out as the most ideal charge carrier for aqueous Zn-organic batteries (ZOBs). Hydrogen-bonding networks with rapid Grotthuss proton conduction is particularly suitable for organic cathodes, yet not reported. We report the supramolecular self-assembly of cyanuric acid and 1,3,5-triazine-2,4,6-triamine into organic superstructures through in-plane H-bonds and out-of-plane π-π interaction. The supramolecular superstructures exhibit highly stable lock-and-key H-bonding networks with an ultralow activation energy for protonation (0.09 eV vs. 0.25 eV of zincification). Then, high-kinetics H+ coordination is prior to Zn2+ into protophilic C=O sites via a two-step nine-electron reaction. The assembled ZOBs show high-rate capability (135 mAh g-1 at 150 A g-1 ), high energy density (267 Wh kg-1 cathode ) and ultra-long life (50 000 cycles at 10 A g-1 ), becoming the state-of-the-art ZOBs in comprehensive performances.

15.
Small ; 18(39): e2204219, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36038354

RESUMO

Chiral inorganic nanomaterials have shown promise as a potential means of combating bacteria due to their high levels of biocompatibility, easy surface modification, and excellent optical properties. In this study, a diverse range of chiral hierarchical nanomaterials are prepared from Co2+ and L/D-Tartaric acid (Tar) ligands. By combining the ligands in different ratios, chiral Co superstructures (Co SS) are obtained with different morphologies, including chiral nanoflowers, chiral nanohanamaki, a chiral six-pointed star, a chiral fan shape, and a chiral fusiform shape. It is found that the chiral six-pointed star structures exhibit chiroptical activity across a broad range of wavelengths from 300 to 1300 nm and that the g-factor is as high as 0.033 with superparamagnetic properties. Under the action of electromagnetic fields, the chiral six-pointed star Co SS shows excellent killing ability against Gram-positive Staphylococcus aureus (ATCC 25923). Compared to L-Co SS, D-Co SS shows stronger levels of antibacterial ability. It is found that the levels of reactive oxygen species generated by D-Co SS are 1.59-fold higher than L-Co SS which is attributed to chiral-induced spin selectivity effects. These findings are of significance for the further development of chiral materials with antibacterial properties.


Assuntos
Antibacterianos , Cobalto , Antibacterianos/química , Antibacterianos/farmacologia , Cobalto/química , Ligantes , Espécies Reativas de Oxigênio , Staphylococcus aureus
16.
Small ; 18(2): e2104477, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34738718

RESUMO

Synthesis of anisotropic carbonaceous nano- and micro-materials with well-ordered mesoporous structures has attracted increasing attention for a broad scope of applications. Although hard-templating method has been widely employed, overcoming the viscous forces to prepare anisotropic mesoporous materials is particularly challenging via the universal soft-templating method, especially from sustainable biomass as a carbon resource. Herein, the synthesis of biomass-derived nanowire-arrays based mesoporous nanorods and teeth-like superstructures is reported, through a simple and straightforward polyelectrolyte assisted soft-templating hydrothermal carbonization (HTC) approach. A surface energy induced interfacial assembly mechanism with the synergetic interactions between micelles, nanowire, nanorods, and polyelectrolyte is proposed. The polyelectrolyte acts not only as a stabilizer to decrease the surface energy of cylindrical micelles, nanowires and nanorods, but also as a structure-directing agent to regulate the oriented attachment and anisotropic assembly of micelles, nanowires, and nanorods. After a calcination treatment, the carbon nanorod and teeth-like superstructure are successfully coupled with Ru to directly produce supported catalysts for the hydrogen evolution reaction, exhibiting much better performance than the isotropic nanospheres based catalyst. This HTC approach will open up new avenues for the synthesis of anisotropic materials with various morphologies and dimensions, expanding the palette of materials selection for many applications.


Assuntos
Nanotubos , Nanofios , Biomassa , Carbono/química , Catálise , Nanotubos/química , Nanofios/química
17.
Small ; 18(1): e2105246, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34741426

RESUMO

Electrocatalytic CO2 reduction reaction (CO2 RR) toward formate production can be operated under mild conditions with high energy conversion efficiency while migrating the greenhouse effect. Herein, an integrated 3D open network of interconnected bismuthene arrays (3D Bi-ene-A/CM) is fabricated via in situ electrochemically topotactic transformation from BiOCOOH nanosheet arrays supported on the copper mesh. The resulted 3D Bi-ene-A/CM consists of 2D atomically thin metallic bismuthene (Bi-ene) in the form of an integrated array superstructure with a 3D interconnected and open network, which harvests the multiple structural advantages of both metallenes and self-supported electrodes for electrocatalysis. Such distinctive superstructure affords the maximized quantity and availability of the active sites with high intrinsic activity and superior charge and mass transfer capability, endowing the catalyst with good CO2 RR performance for stable formate production with high Faradaic efficiency (≈90%) and current density (>300 mA cm-2 ). Theoretical calculation verifies the superior intermediate stabilization of the dominant Bi plane during CO2 RR. Moreover, by further coupling anodic methanol oxidation reaction, an exotic electrolytic system enables highly energy-efficient and value-added pair-electrosynthesis for concurrent formate production at both electrodes, achieving substantially improved electrochemical and economic efficiency and revealing the feasibility for practical implementation.

18.
Small ; 18(10): e2105304, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35032093

RESUMO

The assembly of molecules into hierarchical superstructures is ubiquitous in the construction of novel geometrically complex hierarchical superstructures, attracting great attention. Herein, a metal-ligand cross-linking strategy is developed for the fabrication of ferric ion-dopamine coordination hierarchical superstructures. A range of superstructures with highly complex morphologies, such as flower-like, octopus-like, and hedgehog-like superstructures, are synthesized. The mechanism for formation of hierarchical superstructures involves the pre-cross-linking of ferric ion with dopamine molecules, the fabrication of iron-dopamine precursors aggregated into the spherical aggregates, the nanoscale aggregates sintering and ordering themselves upon equilibration, the nanodots polymerizing into nanorods, and finally the nanorods self-assembling into hierarchical superstructures. In-depth research illustrates that as the permittivity (ξ) of the reaction system increases, the resulting hierarchical superstructures tend to converge into spherical shape. As a proof of concept, the 0D nanospheres, 1D nanorods, and 3D hierarchical superstructures are fabricated through adjusting system permittivity. The hierarchical superstructure is utilized as peroxidase-like ligase mimics to enhance the effect of tumor photothermal treatment. Further in vitro and in vivo assays demonstrate that the hierarchical superstructure can effectively ablate tumor cells. This work opens new horizons in hierarchical superstructures with complex architectures, and has great potential in nanozymology, biomedical science, and catalysis.


Assuntos
Nanotubos , Neoplasias , Proteínas Hedgehog , Humanos , Ligases , Nanotubos/química , Neoplasias/terapia , Terapia Fototérmica
19.
Small ; 18(34): e2203042, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35908802

RESUMO

Transition metal nitrides (TMNs) nanostructures possess distinctive electronic, optical, and catalytic properties, showing great promise to apply in clean energy, optoelectronics, and catalysis fields. Nonetheless, phase-regulation of NiFe-bimetallic nitrides nanocrystals or nanohybrid architectures confronts challenges and their electrocatalytic overall water splitting (OWS) performances are underexplored. Herein, novel pure-phase Ni2+ x Fe2- x N nanocrystals armored with amorphous N-doped carbon (NC) nanoparticles nanocubes (NPNCs) are obtained by controllable nitridation of NiFe-Prussian-blue analogues derived oxides/NC NPNCs under Ar/NH3 atmosphere. Such Ni2+ x Fe2- x N/NC NPNCs possess mesoporous structures and show enhanced electrocatalytic activity in 1 m KOH electrolyte with the overpotential of 101 and 270 mV to attain 10 and 50 mA cm-2 current toward hydrogen and oxygen evolution reactions, outperforming their counterparts (mixed-phase NiFe2 O4 /Ni3 FeN/NC and NiFe oxides/NC NPNCs). Remarkably, utilizing them as bifunctional catalysts, the assembled Ni2+ x Fe2- x N/NC||Ni2+ x Fe2- x N/NC electrolyzer only needs 1.51 V cell voltage for driving OWS to approach 10 mA cm-2 water-splitting current, exceeding their counterparts and the-state-of-art reported bifunctional catalysts-based devices, and Pt/C||IrO2 couples. Additionally, the Ni2+ x Fe2- x N/NC||Ni2+ x Fe2- x N/NC manifests excellent durability for OWS. The findings presented here may spur the development of advanced TMNs nanostructures by combining phase, structure engineering, and hybridization strategies and stimulate their applications toward OWS or other clean energy fields.

20.
Small ; 18(52): e2203147, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36323587

RESUMO

The exploration of electrocatalysts with high catalytic activity and long-term stability for electrochemical energy conversion is significant yet remains challenging. Zeolitic imidazolate framework (ZIF)-derived superstructures are a source of atomic-site-containing electrocatalysts. These atomic sites anchor the guest encapsulation and self-assembly of aspheric polyhedral particles produced using microreactor fabrication. This review provides an overview of ZIF-derived superstructures by highlighting some of the key structural types, such as open carbon cages, 1D superstructures, hollow structures, and the interconversion of superstructures. The fundamentals and representative structures are outlined to demonstrate the role of superstructures in the construction of materials with atomic sites, such as single- and dual-atom materials. Then, the roles of ZIF-derived single-atom sites for the electroreduction of CO2 and electrochemical synthesis of H2 O2 are discussed, and their electrochemical performance for energy conversion is outlined. Finally, the perspective on advancing single- and dual-atom electrode-based electrochemical processes with enhanced redox activity and a low-impedance charge-transfer pathway for cathodes is provided. The challenges associated with ZIF-derived superstructures for electrochemical energy conversion are discussed.

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