Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 134
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Inorg Chem ; 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32410454

RESUMO

Good aqueous dispersibility of metal chalcogenide nanoclusters with an atomically precise structure is desirable to achieve tiny and uniform cluster-based "quantum dots". However, there are big challenges toward this goal, especially for the large-sized nanoclusters without covalently bonded organic ligands, because the strong electrostatic interactions between closely packed negatively charged nanoclusters and protonated organic amine templates in the crystal lattice impede the dispersion of cluster-based bulk crystalline samples. Here, we report two iso-structured crystalline metal chalcogenides composed of discrete supertetrahedral T4-MInS nanoclusters with the formulas of [M4In16S35]14- (denoted ISC-16-MInS, M = Zn and Fe), which adopt a sodalite-net loose-packing pattern in the crystal lattice and display superior dispersibility in water and some organic solvents as compared to other cases composed of the same type of nanoclusters with close-packing pattern. The dispersed T4-MInS nanoclusters were unexpectedly stabilized by adsorbing a certain number of H+ ions on surface S sites and simultaneously dropping partial surface S2- ions, instead of being surrounded by protonated organic amines, which was clearly verified by electrospray ionization mass spectrometry analysis. Notably, ISC-16-ZnInS behaves with superior performance on photodegradation of rhodamine B dye to ISC-16-FeInS. This is attributed to their difference in divalent-metal-directed separation efficiency of the photogenerated electrons and holes. This work holds great promise for the potential functional applications of uniformly dispersed semiconductor nanoclusters, such as cluster-based thin film devices, photoelectrodes, and photocatalysis.

2.
Inorg Chem ; 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32447960

RESUMO

Reported here are two unprecedented copper-rich open-framework chalcogenides constructed from unusual [Cu5(SnxM1-x)Se10] clusters and [(SnxM1-x)2Se6] dimeric linkers (M = In and Ga). The photoresponsive properties in the IR range and the photocatalytic activity for degradation of methylene blue dye of these two isostructural semiconductors were proved to be effectively adjusted by trivalent metal ions in a cluster.

3.
Nanoscale ; 12(16): 8875-8882, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32259173

RESUMO

BiVO4 has been widely used as a photoanode material, while the slow surface oxygen evolution reaction (OER) kinetics still severely hinders its performance. Here, an efficient bimetallic cocatalyst (named FeSnOS) was obtained by post-annealing a Fe/Sn-containing metal chalcogenide coordination compound to enhance the OER activity of BiVO4. The synergistic effect of Fe and Sn species in the amorphous FeSnOS cocatalyst efficiently lowers the interface impedance of the photoanode, reduces the electrochemical reaction overpotential, and promotes the surface OER dynamics. At the same time, a type-II heterojunction was constructed due to the process of post-annealing, which efficiently improves the bulk phase charge separation efficiency of the photoanode. The obtained optimal photoanode (named FeSnOS-BiVO4) shows a photocurrent density of 3.1 mA cm-2 at 1.23 V vs. the reversible hydrogen electrode, which is 3.4 times higher than that of the pristine BiVO4 photoanode, and its onset potential shifts negatively from 0.44 V to 0.25 V. This work presents a simple and effective method to build a bimetallic cocatalyst for improved photoelectrochemical performance, which extends the application of polymetallic metal chalcogenide complexes.

4.
Kaohsiung J Med Sci ; 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32255569

RESUMO

Acute myocardial infarction (AMI) remains one of the leading causes of morbidity and mortality worldwide. Ischemia/reperfusion (I/R), the most common consequence of AMI treatment, may induce severe myocardial cell injury, yet the precise mechanism continues to be enigmatic. In the present study, we found that miR-129-5p was significantly downregulated in mouse I/R model. Then, we overexpressed miR-129-5p via intravenous injection of specific miR-129-5p agomir before I/R model establishment. MiR-129-5p overexpression dramatically alleviated myocardial injury in I/R mice as evidenced by reduced lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) content, and infract size. We further detected the effect of miR-129-5p on hypoxia/reoxygenation (H/R)-induced H9C2 cell in vitro. MiR-129-5p overexpression improved H9C2 cell viability and inhibited cell apoptosis induced by H/R, accompanied with decreased LDH activity and MDA content. Besides, luciferase reporter assay indicated that suppressor of cytokine signaling 2 (SOCS2) was a downstream target of miR-129-5p. SOCS2 was upregulated in H/R induced H9C2 cells, and miR-129-5p overexpression suppressed SOCS2 expression at both mRNA and protein levels. In addition, SOCS2 overexpression abolished the protective effects of miR-129-5p on H/R-induced H9C2 cells, concomitant with elevated expression of apoptosis-related cleaved poly-(ADP-ribose) polymerase and cleaved caspase-3. In conclusion, our results demonstrated that miR-129-5p alleviated myocardial injury induced by I/R both in vitro and in vivo, and miR-129-5p/SOCS2 axis is a potential therapeutic target for alleviating myocardial injury in AMI patients after reperfusion.

5.
Inorg Chem ; 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32207301

RESUMO

Understanding the active species derived from metal-organic frameworks (MOFs) plays a vital role in the fabrication of highly efficient and stable oxygen evolution reaction (OER) electrocatalysts. Herein, a new alkaline-stable 3D nickel metal-organic framework (Ni-MOF), containing a 1D rod-packing chain structure fused with a tetranuclear nickel cluster [Ni4(µ3-OH)2], is used as a target material to explore its OER properties. The electrocatalytic activities of pure Ni-MOF and hybrid materials made from Ni-MOF with different acetylene black loaded electrodes, such as glassy carbon, fluorine-doped tin oxide, and nickel foam, have been evaluated. Further analysis unravels that the enhanced OER performance might be attributed to the synergistic interactions of two catalytic active species between in situ formed ß-Ni(OH)2 and a tetranuclear Ni4(µ3-OH)2 cluster in Ni-MOF. The findings will shed fresh light on the fabrication of MOF-derived catalysts for efficient electrochemical energy conversion.

6.
J Am Chem Soc ; 142(14): 6649-6660, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32176486

RESUMO

Strong Mn-Mn coupling interactions (dipole-dipole and spin-exchange), predominantly determined by statistically and apparently short Mn···Mn distances in traditional heavily Mn2+-doped semiconductors, can promote energy transfer within randomly positioned and close-knit Mn2+ pairs. However, the intrinsic mechanism on controlling Mn2+ emission efficiency is still elusive due to the lack of precise structure information on local tetrahedrally coordinated Mn2+ ions. Herein, a group of Mn2+-containing metal-chalcogenide open frameworks (MCOFs), built from [Mn4In16S35] nanoclusters (denoted T4-MnInS) with a precise [Mn4S] configuration and length-variable linkers, were prepared and selected as unique models to address the above-mentioned issues. MCOF-5 and MCOF-6 that contained a symmetrical [Mn4S] core with a D2d point group and relatively long Mn···Mn distance (∼3.9645 Å) exhibited obvious red emission, while no room-temperature PL emission was observed in MCOF-7 that contained an asymmetric [Mn4S] configuration with a C1 point group and relatively short Mn···Mn distance (∼3.9204 Å). The differences of Mn-Mn dipole-dipole and spin-exchange interactions were verified through transient photoluminescent spectroscopy, electron spin resonance (ESR), and magnetic measurements. Compared to MCOF-5 and MCOF-6 showing a narrower/stronger ESR signal and longer decay lifetime of microseconds, MCOF-7 displayed a much broader/weaker ESR signal and shorter decay lifetime of nanoseconds. The results demonstrated the dominant role of distance-directed Mn-Mn dipole-dipole interactions over symmetry-directed spin-exchange interactions in modulating PL quenching behavior of Mn2+ emission. More importantly, the reported work offers a new pathway to elucidate Mn2+-site-dependent photoluminescence regulation mechanism from the perspective of atomically precise nanoclusters.

7.
Ultrasound Med Biol ; 46(3): 828-841, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31901383

RESUMO

Ultrasound volume projection imaging (VPI) has been recently suggested. This novel imaging method allows a non-radiation assessment of spine deformity with free-hand 3-D ultrasound imaging. This paper presents a fully automatic method to evaluate the spine curve in VPI images corresponding to different projection depth of the volumetric ultrasound, thus making it possible to analyze 3-D spine deformity. The new automatic method is based on prior knowledge about the geometric arrangement of the spinous processes. The frequency bandwidth of log-Gabor filters is adaptively adjusted to calculate the oriented phase congruency, facilitating the segmentation of the spinous column profile. And the spine curvature angle is finally calculated according to the inflection points of the curve over the segmented spinous column profile. The performance of the automatic method is evaluated on spine VPI images among patients with different scoliotic angles. The curvature angles obtained using the proposed method have a high linear correlation with those by the manual method (r = 0.90, p < 0.001) and X-ray Cobb's method (r = 0.87, p < 0.001). The feasibility of 3-D spine deformity assessment is also demonstrated using VPI images corresponding to various projection depth. The results suggest that this method can substantially improve the recognition of the spinous column profile, especially facilitating the applications of 3-D spine deformity assessment.

8.
J Org Chem ; 85(1): 291-295, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31797673

RESUMO

The synthesis and properties of a series of U-shaped helical azaarenes are reported. Crystal structures of these helical azaarenes were obtained, and the solid-state structures unequivocally exhibited their helicity.

9.
ChemSusChem ; 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31782976

RESUMO

Searching new organic cathode materials to address the issues of poor cycle stability and low capacity in lithium ion batteries (LIBs) is very important and highly desirable. In this research, a 2D boroxine-linked chemically-active pyrene-4,5,9,10-tetraone (PTO) covalent organic framework (2D PPTODB COFs) was synthesized as an organic cathode material with remarkable electrochemical properties, including high electrochemical activity (four redox electrons), safe oxidation potential window (between 2.3 and 3.08 V vs. Li/Li+ ), superb structural/chemical stability, and strong adhesiveness. A binder-free cathode was obtained by mixing 70 wt % PPTODB and 30 wt % carbon nanotubes (CNTs) as a conductive additive. Promoted by the fast kinetics of electrons/ions, high electrochemical activity, and effective π-π interaction between PPTODB and CNTs, LIBs with the as-prepared cathode exhibited excellent electrochemical performance: a high specific capacity of 198 mAh g-1 , a superb rate ability (the capacity at 1000 mA g-1 can reach 76 % of the corresponding value at 100 mA g-1 ), and a stable coulombic efficiency (≈99.6 % at the 150th cycle). This work suggests that the concept of binder-free 2D electroactive materials could be a promising strategy to approach energy storage with high energy density.

10.
Small ; 15(49): e1903188, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31650707

RESUMO

Conjugated coordination polymers have become an emerging category of redox-active materials. Although recent studies heavily focus on the tailoring of metal centers in the complexes to achieve stable electrochemical performance, the effect on different substitutions of the bridging bonds has rarely been studied. An innovative tailoring strategy is presented toward the enhancement of the capacity storage and the stability of metal-organic conjugated coordination polymers. Two nanostructured d-π conjugated compounds, Ni[C6 H2 (NH)4 ]n (Ni-NH) and Ni[C6 H2 (NH)2 S2 ]n (Ni-S), are evaluated and demonstrated to exhibit hybrid electrochemical processes. In particular, Ni-S delivers a high reversible capacity of 1164 mAh g-1 , an ultralong stability up to 1500 cycles, and a fully recharge ability in 67 s. This tailoring strategy provides a guideline to design future effective conjugated coordination-polymer-based electrodes.

11.
Inorg Chem ; 58(18): 12415-12421, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31483642

RESUMO

Many strategies to optimize molybdenum selenide based electrocatalysts for hydrogen evolution reaction (HER) have been explored; however, the modulation of molybdenum selenide on the molecular scale remains an ongoing challenge. Here, we synthesized a new molecular HER electrocatalyst based on a molybdenum-selenium cluster (Mo3Se13) and further realized its modulation by precise sulfur substitution at the molecular level to enhance the HER activity. The density functional theory (DFT) calculations demonstrated that the substituted sulfur could promote the hydrogen adsorption process and thus improve the HER performance. This work not only realizes the selective replacement of the bridging selenium atom with a sulfur atom in the molybdenum-selenium cluster for the first time but also provides a precise model for illustrating the structure-property relationship in electrocatalysis on the molecular level.

12.
J Exp Clin Cancer Res ; 38(1): 394, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492191

RESUMO

BACKGROUND: FAM92A1-289(abbreviated FAM289) is recognized as one of the newly-discovered putative oncogenes. However, its role and molecular mechanisms in promoting cancer progression has not yet been elucidated. This study was performed to reveal its oncogenic functions and molecular mechanisms in human glioblastoma multiforme (GBM) cell models with knockdown or overexpression of FAM289 in vitro and in vivo. METHODS: To elucidate the molecular mechanisms underlying FAM289-mediated tumor progression, the protein-protein interaction between FAM289 and Galectin-1 was verified by co-immunoprecipitation, followed by an analysis of the expression and activity of Galectin-1-associated signaling molecules. Knockdown and overexpression of FAM289 in glioma cells were applied for investigating the effects of FAM289 on cell growth, migration and invasion. The determination of FAM289 expression was performed in specimens from various stages of human gliomas. RESULTS: FAM289-galectin-1 interaction and concomitant activation of the extracellular signal-regulated kinase (ERK) pathway participated in FAM289-mediated tumor-promoting function. Since the expression of DNA methyl transferase 1 (DNMT1) and DNA methyl transferase 3B (DNMT3B) was regulated by FAM289 in U251 and U87-MG glioma cells, Galectin-1 interaction with FAM289 may promote FAM289 protein into the cell nucleus and activate the ERK pathway, thereby upregulating DNMTs expression. Drug resistance tests indicated that FAM289-mediated TMZ resistance was through stem-like property acquisition by activating the ERK pathway. The correlation between FAM289, Galectin-1 expression and the clinical stage of gliomas was also verified in tissue samples from glioblastoma patients. CONCLUSIONS: Our results suggest that high expression of FAM289 in GBM tissues correlated with poor prognosis. FAM289 contributes to tumor progression in malignant glioma by interacting with Galectin-1 thereby promoting FAM289 protein translocation into the cell nucleus. FAM289 in the nucleus activated the ERK pathway, up regulated DNMTs expression and induced stem-like property gene expression which affects drug resistance of glioma cells to TMZ. This study provided functional evidence for FAM289 to be developed as a therapeutic target for cancer treatment.


Assuntos
Galectina 1/metabolismo , Glioma/genética , Glioma/metabolismo , Proteínas/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Progressão da Doença , Técnicas de Silenciamento de Genes , Glioma/patologia , Humanos , Camundongos , NF-kappa B/metabolismo , Metástase Neoplásica , Estadiamento de Neoplasias , Ligação Proteica , Transdução de Sinais
13.
Angew Chem Int Ed Engl ; 58(35): 12185-12189, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31286629

RESUMO

Embedding cubane [M4 (OH)4 ] (M=Ni, Co) clusters within the matrix of metal-organic frameworks (MOFs) is a strategy to develop materials with unprecedented synergistic properties. Herein, a new material type based on the pore-space partition of the cubic primitive minimal-surface net (MOF-14-type) has been realized. CTGU-15 made from the [Ni4 (OH)4 ] cluster not only has very high BET surface area (3537 m2 g-1 ), but also exhibits bi-microporous features with well-defined micropores at 0.86 nm and 1.51 nm. Furthermore, CTGU-15 is stable even under high pH (0.1 m KOH), making it well suited for methanol oxidation in basic medium. The optimal hybrid catalyst KB&CTGU-15 (1:2) made from ketjen black (KB) and CTGU-15 exhibits an outstanding performance with a high mass specific peak current of 527 mA mg-1 and excellent peak current density (29.8 mA cm-2 ) at low potential (0.6 V). The isostructural cobalt structure (CTGU-16) has also been synthesized, further expanding the application potential of this material type.

14.
Inorg Chem ; 58(15): 9543-9547, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31343166

RESUMO

Exploring high-performance metal-organic frameworks (MOFs) for pseudocapacitors is quite meaningful for energy storage. Herein a bimetal NiCo-MOF with ultrathin thickness was prepared via a simple hydrothermal method, which shows excellent electrochemical performance with specific capacitances of 1945.83 and 1700.40 F/g at current densities of 0.5 and 1 A/g, respectively, while maintaining good stability. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy spectra unravel that the strong coupling between Ni and Co species enhances the valence state of Ni2+ in the ultrathin nanosheets, which facilitates the charge transfer during the electrochemical reaction and results in greatly improved pseudocapacitive reactivity. This work provides guidance on the promising prospect of MOF materials for pseudocapacitor applications.

15.
Chem Asian J ; 14(20): 3694-3701, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31347761

RESUMO

Effective detection of organic/inorganic pollutants, such as antibiotics, nitro-compounds, excessive Fe3+ and MnO4 - , is crucial for human health and environmental protection. Here, a new terbium(III)-organic framework, namely [Tb(TATAB)(H2 O)]⋅2H2 O (Tb-MOF, H3 TATAB=4,4',4''-s-triazine-1,3,5-triyltri-m-aminobenzoic acid), was assembled and characterized. The Tb-MOF exhibits a water-stable 3D bnn framework. Due to the existence of competitive absorption, Tb-MOF has a high selectivity for detecting Fe3+ , MnO4 - , 4-nirophenol and nitroimidazole (ronidazole, metronidazole, dimetridazole, ornidazole) in aqueous through luminescent quenching. The results suggest that Tb-MOF is a simple and reliable reagent with multiple sensor responses in practical applications. To the best of our knowledge, this work represents the first TbIII -based MOF as an efficient fluorescent sensor for detecting metal ions, inorganic anions, nitro-compounds, and antibiotics simultaneously.

16.
Mol Med Rep ; 20(1): 633-639, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31180542

RESUMO

Mesenchymal stem cells (MSCs) are derived from the mesoderm and have the self­renewal capacity and multi­directional differentiation potential of adult stem cells. Stem cells from different sources have different molecular and growth characteristics; therefore, the mechanisms and effects of stem cell­mediated repair and tissue regeneration may be different. The aim of the present study was to compare the biological characteristics of MSCs derived from the umbilical cord (UC­MSCs) and MSCs derived from the decidua parietalis (DP­MSCs), and to provide new evidence for the selection of seed cells in regenerative medicine. Growth curves, cell doubling times, colony formation rates, immunophenotypes, differentiation capacities and secretion­factor levels of MSCs derived from the two sources were analysed. UC­MSCs and DP­MSCs exhibited similar properties with regards to morphology, spiral growth, immunophenotype, and potential to differentiate into osteoblasts and adipocytes. For each cell type, the positive rates of the cell surface markers CD73, CD90 and CD105 were >95%, whereas CD34 and CD45 positive rates were <1%. Analyses of in vitro growth kinetics revealed shorter cell­doubling times, and higher proliferative rates and colony formation rates of UC­MSCs compared with DP­MSCs (P<0.05). The concentration of basic fibroblast growth factor in the supernatant from UC­MSCs was higher compared with that from DP­MSCs (P<0.05). However, UC­MSC supernatants exhibited lower levels of of keratinocyte growth factor, vascular endothelial growth factor and stem cell factor compared with DP­MSCs (P<0.05). In conclusion, in vitro characterization of MSCs from these tissue sources revealed a number of common biological properties. However, the results also demonstrated clear biological distinctions and suggested that UC­MSCs may have more effective application prospects.


Assuntos
Decídua/citologia , Células-Tronco Mesenquimais/citologia , Cordão Umbilical/citologia , Adipogenia , Antígenos CD/análise , Proliferação de Células , Células Cultivadas , Citocinas/análise , Feminino , Humanos , Imunofenotipagem , Osteogênese
17.
Medicine (Baltimore) ; 98(23): e15935, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31169714

RESUMO

BACKGROUND: Patients requiring posterior lumbar surgery have increased annually. Incision infection after lumbar surgery has serious consequences for patients. However, data on the related factors of incision infection after lumbar surgery in diabetic patients are limited. Therefore, this study aimed to analyze diabetic patients who underwent lumbar surgery and to explore the risk factors of perioperative incision infection to provide a scientific basis for perioperative intervention of lumbar spine surgery and reduce risk of incision infection in such patients. METHODS: We retrospectively reviewed data of diabetic patients who underwent posterior lumbar surgery from 2011 to 2016. A total of 523 diabetic patients undergoing posterior lumbar surgery were analyzed for the influence of various risk factors on postoperative incision infection. Univariate and multivariate logistic regression was performed. The test level was α=.05, and P < .05 was considered statistically significant. RESULTS: In the past 6 years, among the 523 diabetic patients, the incidence of incision infection after posterior lumbar surgery was approximately 7.1%, of which the shallow incision infection rate was 4.2% and the deep incision infection rate was 2.9%. Incision infection of posterior lumbar surgery in diabetic patients is related to smoking, preoperative glycosylated hemoglobin A1c, postoperative albumin (Alb), surgical segment, operation time, and intraoperative blood loss, especially on postoperative fasting blood glucose, postoperative postprandial blood glucose, local subcutaneous fat thickness, and operation sequence (odds ratio >5.00). Meanwhile, sex, age, body mass index (BMI), preoperative Alb, and newly diagnosed diabetes were not highly correlated with incision infection after posterior lumbar surgery. CONCLUSION: Local subcutaneous fat thickness is a better indicator for predicting incision infection compared with BMI. In diabetic patients undergoing lumbar surgery, actively controlling blood glucose fluctuations, restoring normal diet early after surgery, and optimizing surgical procedures to reduce trauma and operative time can effectively reduce the risk of infection after posterior lumbar surgery.


Assuntos
Complicações do Diabetes/cirurgia , Diabetes Mellitus/cirurgia , Vértebras Lombares/cirurgia , Procedimentos Neurocirúrgicos/efeitos adversos , Infecção da Ferida Cirúrgica/etiologia , Idoso , Glicemia , Índice de Massa Corporal , Complicações do Diabetes/sangue , Complicações do Diabetes/patologia , Diabetes Mellitus/sangue , Diabetes Mellitus/patologia , Feminino , Hemoglobina A Glicada/análise , Humanos , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Procedimentos Neurocirúrgicos/métodos , Estudos Retrospectivos , Fatores de Risco , Gordura Subcutânea/patologia , Infecção da Ferida Cirúrgica/sangue , Infecção da Ferida Cirúrgica/epidemiologia
18.
Chem Commun (Camb) ; 55(56): 8146-8149, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31240283

RESUMO

Herein, we report a simple, yet highly effective approach for constructing a new type of sub-nanoscale ZnS/ZnO heterojunction (∼2-4 nm) with highly rich interfaces by photoetching hybrid Zn-S-O molecular clusters. The obtained ZnS/ZnO heterojunctions with ZnS spheres decorated with ultrasmall amorphous ZnO dots exhibit superior photocatalytic performance (∼94.0 µmol g-1 h-1), compared to nanoscale homologous samples obtained via conventional heat treatment (∼17.0-21.4 µmol g-1 h-1). Such a light-triggered molecular-cluster-to-heterojunction strategy provides a synthetic approach to building other sub-nanoscale hetero-structured materials for further promoting the catalytic-related applications.

19.
Chem Commun (Camb) ; 55(45): 6357-6360, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31065633

RESUMO

Here we report two new metal-chalcogenide open frameworks (MCOFs) with large-sized supertetrahedral clusters bridged by an accessible single-cuprous ion via a multivalent mixed-metal strategy. Such Cu-rich semiconductor MCOFs have been investigated for the first time for nonenzymatic detection of glucose, and display good sensitivity and stability.


Assuntos
Calcogênios/química , Cobre/química , Glucose/análise , Estruturas Metalorgânicas/química
20.
Inorg Chem ; 58(9): 5837-5843, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-30995020

RESUMO

Developing high-efficiency and cost-effective electrocatalytic oxygen evolution reaction (OER) catalysts would determine the future distributions of energy conversion technologies. Metal-organic frameworks (MOFs), with unsaturated active metal sites, functionalized organic linkers, and large surface areas, are emerging heterogeneous electrocatalysts for the water oxidation process. Herein, we report an oxygen-evolving microporous (3,10)-connected Co6-based MOF (denoted as CTGU-14) for the electrocatalytic OER. Moreover, the integration of Co-MOF and SnO2, SnO2 (15%) & CTGU-14 composite attains remarkable electrochemical OER performance with a small Tafel slope of 68 mV·dec-1, a positive overpotential of 388 mV at 10 mA·cm-2, and overall durability in an alkali medium. The superior OER activities might be ascribed to more convenient electron transfer from the SnO2 additive to the electrode medium, effective surface area and unsaturated active cobalt centers, and more beneficial delivery for hydroxy radicals in the microporous Co-MOF skeleton in the process of the OER.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA