Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Chemistry ; 30(32): e202400372, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38716721

RESUMO

Perovskite light-emitting diodes (PeLEDs) have gained significant attention due to their promising optoelectronic properties and potential applications in the fields of lighting and display devices. Despite their potential, PeLEDs face challenges related to stability, high turn-on voltage, and low external quantum efficiency (EQE) which has restricted their broad acceptance. Most research efforts have predominantly focused on refining the properties of the perovskite films. However, it is becoming more apparent that interfacial layers and device architecture are crucial for achieving stability and high efficiency, making them indispensable components in PeLED development. This perspective highlights remarkable advancements in PeLED devices, with a primary focus on modifying adjacent layers interfacing with the perovskite film.

2.
Angew Chem Int Ed Engl ; 63(21): e202401118, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38433100

RESUMO

Inorganic zeolites have excellent molecular sieving properties, but they are difficult to process into macroscopic structures. In this work, we use metal-organic framework (MOF) glass as substrates to engineer the interface with inorganic zeolites, and then assemble the discrete crystalline zeolite powders into monolithic structures. The zeolites are well dispersed and stabilized within the MOF glass matrix, and the monolith has satisfactory mechanical stabilities for membrane applications. We demonstrate the effective separation performance of the membrane for 1,3-butadiene (C4H6) from other C4 hydrocarbons, which is a crucial and challenging separation in the chemical industry. The membrane achieves a high permeance of C4H6 (693.00±21.83 GPU) and a high selectivity over n-butene, n-butane, isobutene, and isobutane (9.72, 9.94, 10.31, and 11.94, respectively). This strategy opens up new possibilities for developing advanced membrane materials for difficult hydrocarbon separations.

3.
J Org Chem ; 88(4): 2296-2305, 2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36727513

RESUMO

A simple and efficient electrochemical sulfonylation of organoboronic acids with sodium arylsulfinate salts has been reported for the first time. A variety of aryl, heteroaryl, and alkenylsulfones were obtained in good to excellent yields via a simple electrochemical sulfonylation of various arylboronic acids, heterocyclic boronic acids, or alkenylboronic acids with sodium arylsulfinate at room temperature in 5 h under the catalyst-free and additive-free conditions. A plausible mechanism has been proposed based on various radical-trapping and CV control experiments.

4.
Inorg Chem ; 61(30): 11667-11674, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35862437

RESUMO

A detailed study of the two-dimensional (2-D) Hofmann-like framework [Fe(furpy)2Pd(CN)4]·nG (furpy: N-(pyridin-4-yl)furan-2-carboxamide, G = H2O,EtOH (A·H2O,Et), and H2O (A·H2O)) is presented, including the structural and spin-crossover (SCO) implications of subtle guest modification. This 2-D framework is characterized by undulating Hofmann layers and an array of interlayer spacing environments─this is a strategic approach that we achieve by the inclusion of a ligand with multiple host-host and host-guest interaction sites. Variable-temperature magnetic susceptibility studies reveal an asymmetric multistep SCO for A·H2O,Et and an abrupt single-step SCO for A·H2O with an upshift in transition temperature of ∼75 K. Single-crystal analyses show a primitive orthorhombic symmetry for A·H2O,Et characterized by a unique FeII center─the multistep SCO character is attributed to local ligand orientation. Counterintuitively, A·H2O shows a triclinic symmetry with two inequivalent FeII centers that undergo a cooperative single-step high-spin (HS)-to-low-spin (LS) transition. We conduct detailed structure-function analyses to understand how the guest ethanol influences the delicate balance between framework communication and, therefore, the local structure and spin-state transition mechanism.

5.
Chemistry ; 27(16): 5136-5141, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33543525

RESUMO

Foremost, practical applications of spin-crossover (SCO) materials require control of the nature of the spin-state coupling. In existing SCO materials, there is a single, well-defined dimensionality relevant to the switching behavior. A new material, consisting of 1,2,4-triazole-based trimers coordinated into 1D chains by [Au(CN)2 ]- and spaced by anions and exchangeable guests, underwent SCO defined by elastic coupling across multiple dimensional hierarchies. Detailed structural, vibrational, and theoretical studies conclusively confirmed that intra-trimer coupling was an order of magnitude greater than the intramolecular coupling, which was an order of magnitude greater than intermolecular coupling. As such, a clear hierarchy on the nature of elastic coupling in SCO materials was ascertained for the first time, which is a necessary step for the technological development of molecular switching materials.

6.
Ying Yong Sheng Tai Xue Bao ; 33(12): 3388-3394, 2022 Dec.
Artigo em Zh | MEDLINE | ID: mdl-36601845

RESUMO

The utilization of sewage sludge in forests is an important way of recycling. However, the effect of sewage sludge application on woody plant root growth has been rarely reported. The effects of surface application and mixed application of sewage sludge (mass ratio in 10%) on the dynamics in root morphology of a fast-growing tree species (Neolamarckia cadamba), soil pH, electric conductivity, and heavy metal content of roots in different soil layers were analyzed by a rhizobox experiment. The relationship between root length and soil pH value, electric conducti-vity, and root heavy metal content were further analyzed. Results showed that mixed application of sewage sludge inhibited root length, root surface area, and root volume. After 120 and 240 days of mixed application, total root length in the 0-20 cm soil layer was 76.9% and 67.4% of that of no sewage sludge application, respectively. Surface application of sewage sludge did not affect root length and root surface area but increased root volume. The mixed application of sewage sludge significantly increased soil pH, electric conductivity, and root heavy metal content. Root Cd contents in 0-20 cm and 20-40 cm soil layers with the mixed application of sewage sludge were 11.5 and 10.0 times as that of no sewage sludge application, respectively. Soil electric conductivity had a significant nega-tive correlation with root length in 0-20 cm soil layer among different treatments. Root Cd content had a significant negative correlation with root length in both the surface and the mixed applications of sewage sludge. These results indicated that mixed application of sewage sludge could inhibit N. cadamba root growth mainly by increasing soil electric conductivity and root Cd content, while the surface application of sewage sludge did not affect root growth.


Assuntos
Metais Pesados , Poluentes do Solo , Poluentes do Solo/análise , Esgotos/química , Cádmio , Solo/química , Metais Pesados/análise
7.
Dalton Trans ; 51(25): 9596-9600, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35670370

RESUMO

Inclusion of an angular bridging ligand, 4,2':6',4''-terpyridine (TPy), into a Hofmann-type framework produces an irregular network in which six- and five-coordinate FeII species co-exist. The octahedral sites show thermally-induced spin-crossover (SCO) and the rare five-coordinate FeII sites are high-spin.

8.
Materials (Basel) ; 14(22)2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34832356

RESUMO

Alkaline electrolyzed water, a kind of clean green water with excellent characteristics such as high activity, strong alkalinity, high ion penetrating ability, electrical charge, and good molecule adsorption, was significant to the resource utilization of industrial fly ash waste. This paper studies highly active potassium-based alkaline electrolyzed water's impact, compared with ordinary water, on the cement hydration process using microstructural methods such as a hydration heat test, differential thermal analysis, X-ray diffraction (XRD) pattern, and Scanning electron microscope (SEM) image analysis. Fly ash cement-based materials were first prepared with alkaline electrolyzed water as the mixing water. The alkaline electrolyzed water's influence on fly ash paste workability and the mechanical properties of fly ash mortar for varying fly ash proportions were ratified. Then alkaline electrolyzed water with the best pH value was selected to prepare fly ash concrete, and its durability was studied. The test results showed that it is feasible to increase the utilization rate of fly ash by using alkaline electrolyzed water. Furthermore, it promoted the process of cement hydration, increased the rate of the hydration reaction, and the promotion effect increased with the increase in pH value of the alkaline electrolyzed water, and also promoted the effective decomposition of the vitreous shell of fly ash to stimulate its early activity. Concurrent tests with ordinary water paste showed that the water requirement for normal consistency and setting time with alkaline electrolyzed water paste were significantly less. Alkaline electrolyzed water also solved the problem related to the low early strength of fly ash mortar. Furthermore, using alkaline electrolyzed water with an optimum pH value of 11.5 to prepare fly ash concrete effectively reduced concrete's carbonation depth and carbonation rate and lessened the chloride ion migration coefficient.

9.
Chem Commun (Camb) ; 57(1): 85-88, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33245087

RESUMO

A 3-D FeII Hofmann-type framework material has been prepared which contains a three-connecting pyridyl-donor ligand with amide functionality and [Au(CN)2]- metallo-ligands. The FeII sites display a rare FeII(py)3(N[triple bond, length as m-dash]C)3 coordination environment, which we show for the first time to be conducive to spin crossover (SCO).

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA