The integration of metal/metal oxide nanoparticles (NPs) into metal–organic frameworks (MOFs) to form composite materials has attracted great interest due to the broad range of applications. However, ...to date, it has not been possible to encapsulate metastable NPs with high catalytic activity into MOFs, due to their instability during the preparation process. For the first time, we have successfully developed a template protection–sacrifice (TPS) method to encapsulate metastable NPs such as Cu2O into MOFs. SiO2 was used as both a protective shell for Cu2O nanocubes and a sacrificial template for forming a yolk–shell structure. The obtained Cu2O@ZIF‐8 composite exhibits excellent cycle stability in the catalytic hydrogenation of 4‐nitrophenol with high activity. This is the first report of a Cu2O@MOF‐type composite material. The TPS method provides an efficient strategy for encapsulating unstable active metal/metal oxide NPs into MOFs or maybe other porous materials.
Three birds with one stone: A template protection–sacrifice method was developed to encapsulate metastable metal/metal oxide nanoparticles such as Cu2O into metal–organic frameworks. SiO2 serves as a sacrificial template for forming the yolk–shell structure, as a protective shell for Cu2O nanocubes, and as a space holder in the porous composite.
In the surroundings of carbon neutrality, nano‐Cu2O is considered a promising catalyst for the electrochemical CO2 reduction reaction (ECO2RR), whose improvements in product selectivity still require ...considerable efforts. Here, we present an efficient strategy for controlling the ECO2RR product by modifying the surface of nano‐Cu2O, i.e., by controlling the exposed facets via a reductant‐controlled method to achieve the highest C2H4 selectivity (Faradic efficiency=74.1 %) for Cu2O‐based catalysts in neutral electrolytes, and introducing a well‐suited metal–organic framework (MOF) coating on the surface of nano‐Cu2O to obtain syngas completely with an appropriate H2:CO ratio. Detailed mechanism and key intermediate have been illustrated by DFT calculations. Our systematic strategy is expected to control the ECO2RR product, improve the selectivity, and provide a reliable method for CO2 management and the green production of important carbon resources.
Electrochemical CO2 reduction reaction (ECO2RR) with controllable production of important carbon resources was achieved by a surface modification strategy of nano‐Cu2O catalysts. Through facet controlling the highest C2H4 selectivity among Cu2O‐based catalysts was achieved, while the products were completely converted to syngas with an appropriate H2:CO ratio via a MOF coating on the surface of the nano‐Cu2O.
Materials both Tough and Soft Ping Gong, Jian
Science (American Association for the Advancement of Science),
04/2014, Letnik:
344, Številka:
6180
Journal Article
Recenzirano
Tough elastomers are created by adapting an approach previously used for hydrogels.
Also see Report by
Ducrot
et al.
Hydrogels and elastomers are soft materials that have similar network structures ...but very different affinities to water. Consisting mostly of water, hydrogels resemble biological soft tissues and have great potential for use in biomedical applications; they tend to be very brittle, like fragile jellies. Elastomers are formed of nonhydrated polymer networks and are widely used as load-dispersing and shock-absorbing materials. They are stretchable but break easily along a notch. On page 186 of this issue, Ducrot
et al.
(
1
) show that the toughness of elastomers can be improved substantially by combining two different network materials, an approach previously applied to hydrogels.
Metal–organic frameworks (MOFs) are constructed by periodically alternate metal ions with organic ligands, which offer structural diversity and a wide range of interesting properties as an attractive ...classification of crystalline porous materials. Integration of MOFs with other size‐limited functional centers can supply new multifunctional composites, which exhibit both the properties of the components and new characteristics due to the combination of MOFs with the selected loadings. In recent years, integration of metal/metal oxide nanoparticles (MNPs) into MOFs to form the composite catalysts has attracted considerable attention due to the superior performance. In this review, the latest studies and up‐to‐date developments on the design and synthetic strategy of new MNP@MOF composite catalysts are specifically highlighted. Both the achievements and problems are evaluated and proposed, and the opportunities and challenges of MNP@MOF composite catalysts are discussed.
The incorporation of metal and/or metal oxide nanoparticles (MNPs) into metal–organic frameworks (MOFs) to form composite catalysts has received increasing attention because of their excellent catalytic performance compared to the corresponding individual components. In this review, the latest research and recent developments in the design and synthesis strategies of MNP@MOF composite catalysts are highlighted.
Pediatric neurosurgery, encompassing a range of conditions such as childhood brain tumors, congenital neural tube defects, hydrocephalus, traumatic brain injury and cerebrovascular diseases, has seen ...considerable advancement in China since its inception in 1960. Through sustained efforts across generations of physicians, the field has evolved from nonexistence to a position of strength, currently leading globally in the volume and diversity of clinical cases. Despite these strides, challenges persist, notably the shortage of specialized surgeons, regional discrepancies in medical care standards, and a dearth of clinical guidelines. The advent of technologies such as artificial intelligence, brain⁃computer interfaces, and virtual reality presents unprecedented opportunities for rapid advancements in diagnosis and treatment standards. The onus lies on China's pediatric neurosurgery community to leverage this technological evolution, and fulfill their collective mission and responsibility.
Metal-organic frameworks (MOFs) have risen as a kind of porous materials that are constructed by the coordination of organic ligands to metal centers or clusters, providing compelling potential for ...various fields of research. In this frontier article, we demonstrate the recent developments in MOF-based materials for electrochemical sensing applications, and the current challenges and some prospects in this field are also discussed.
A summary of the most recent advancements of metal-organic frameworks (MOFs) for electrochemical sensing is listed in this frontier article.
Silver nanoparticles were successfully supported on the zeolite‐type metal–organic framework MIL‐101 to yield Ag@MIL‐101 by a simple liquid impregnation method. For the first time, the conversion of ...terminal alkynes into propiolic acids with CO2 was achieved by the use of the Ag@MIL‐101 catalysts. Owing to the excellent catalytic activity, the reaction proceeded at atmospheric pressure and low temperature (50 °C). The Ag@MIL‐101 porous material is of outstanding bifunctional character as it is capable of simultaneously capturing and converting CO2 with low energy consumption and can be recovered easily by centrifugation.
Silver nanoparticles were supported on the zeolite‐type metal–organic framework MIL‐101 by a simple liquid impregnation method to yield Ag@MIL‐101. CO2 and terminal alkynes could be converted into propiolic acids in the presence of the very active Ag@MIL‐101 catalyst at atmospheric pressure and low temperature (50 °C).
The practical use of luminescent mononuclear gold(I) complexes as optoelectronic materials has been limited by their inferior stability. Herein we demonstrate a strategy to improve the stability of ...gold(I) complexes which display thermally activated delayed fluorescence (TADF). A highly rigid and groove‐like σ‐donating aryl ligand has been used to form dual Au⋅⋅⋅H−C hydrogen bonds. The secondary metal‐ligand interactions have been authenticated by single‐crystal structure, NMR spectroscopy and theoretical simulations. The TADF AuI complex exhibits appealing emission properties (photoluminescence quantum yield=76 %; delayed fluorescence lifetime=1.2 μs) and much improved thermal and photo‐stability. Vacuum‐deposited organic light‐emitting diodes (OLEDs) show promising electroluminescence with a maximum external quantum efficiency (EQE) over 23 % and negligible efficiency roll‐off even at 10 000 cd m−2. An estimated LT50 longer than 77 000 h with initial luminance of 100 cd m−2 reveals good operational stability. This work suggests a way for design of stable luminescent gold(I) complexes.
Robust mononuclear AuI emitters are prepared by harnessing intramolecular Au⋅⋅⋅H−C interactions. The new emitter displays appealing thermally activated delayed fluorescence (TADF) as well as thermal and photo‐stability, leading to high‐performance organic light‐emitting diodes with negligible efficiency roll‐off and good operational stability. This work shows the potential of secondary interactions for developing optoelectronic materials.
Using data of online ticket sales for attractions in the seven provinces of South Central China, this study focuses on the impact of COVID-19 on tourists' destination preferences after the end of ...lockdown. Empirical results reveal that tourists' destination preferences have changed significantly, which holds under a number of robustness checks. Specifically, we find that tourists avoid traveling to destinations with more confirmed cases of COVID-19 relative to their places of origin, especially Hubei Province, and prefer destinations close to home, especially local attractions. The empirical findings have significant implications for managers and policymakers in tourism and we provide potential mechanisms for these findings based on signaling, risk perception, and prospect theory.
•Tourists' destination preferences are significantly reshaped by the COVID-19 pandemic.•Tourists less prefer destinations with more confirmed COVID-19 cases, especially Hubei Province.•Tourists more prefer destinations close to home, especially the local attractions.•Underlying mechanisms are proposed based on signaling, risk perception, and prospect theory.
Underwater adhesives are in high demand in both commercial and industrial sectors. Compared with adhesives used in dry (air) environments, adhesives used for wet or submerged surfaces in aqueous ...environments have specific challenges in development and performance. In this review, focus is on adhesives demonstrating macroscopic adhesion to wet/underwater substrates. The current strategies are first introduced for different types of underwater adhesives, and then an overview is provided of the development and performance of underwater adhesives based on different mechanisms and strategies. Finally, the possible research directions and prospects of underwater adhesives are discussed.
Underwater adhesives are in high demand from medical to ocean technology. Key specific challenges are discussed to achieve underwater adhesion, and then an overview of strategies of the existing research and the performances of underwater adhesives achieved is presented. Finally, the possible solutions for the challenges, along with future research directions are discussed.
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