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1.
Inorg Chem ; 61(8): 3736-3745, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35175759

RESUMO

Constructing high-quality white organic light-emitting diodes (WOLEDs) remains a big challenge because of high demands on the electroluminescence (EL) performance including high efficiency, excellent spectral stability, and low roll-off simultaneously. To achieve effective energy transfer and trap-assisted recombination in the emissive layer, herein, four Ir(III) phosphors, namely, mOMe-Ir-PI (1), pOMe-Ir-PI (2), mOMe-Ir-PB (3), and pOMe-Ir-PB (4), were strategically designed via simple regulation of the substituent moiety and π conjugation of the chelated ligands. Their photophysical and EL properties were systematically investigated. When these phosphors are employed as doped emitters, the monochromic green organic light-emitting diodes not only exhibit a superior performance with the characteristics of 50.2 cd A-1, 39.2 lm W-1, and 15.1%, but also maintain a negligible roll-off ratio of 0.2% at 1000 cd m-2, which are better than those of commercial green Ir(ppy)2acac and Ir(ppy)3 in the same device configuration. Inspired by these outstanding performances, we successfully fabricated the warm WOLED utilizing 2 as a green component, affording a peak efficiency of 42.0 cd A-1, 29.3 lm W-1, and 18.6% and retaining at 39.9 cd A-1, 23.7 lm W-1, and 17.4% even at 1000 cd m-2. The results herein demonstrate the superiority of the molecular design and propose a simple method toward the development of promising Ir(III) phosphors for high-efficiency WOLEDs.

2.
ACS Appl Mater Interfaces ; 14(5): 6476-6483, 2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35077129

RESUMO

The direct usage of CO2 in the flue gas to produce fuels or chemicals is of great significance from energy-saving and low-cost perspectives, yet it is still underexplored. Herein, we report the photoreduction of CO2 from the simulated industrial exhaust by synergistic catalysis of TEOA and a metal-free composite (COF1-g-C3N4) fabricated via covalently grafting COF1 with g-C3N4. The hydrogen bond interaction between TEOA and hydrazine units on COF1 is detected in diluted CO2, which leads to significantly enhanced light absorption in the whole visible-light region. Also, the photo-induced electrons undergo fast transfer from COF1 to g-C3N4. This kind of dynamic interface with enhanced light absorption and electron transfer effects promotes the photosynthetic yield of syngas to 165.6 µmol·g-1·h-1 with the use of simulated exhaust gas as a raw material directly. The photosynthetic yield of syngas ranks among the highest of known metal-free catalysts in diluted CO2. This work provides a general rule for designing efficient catalysts via a controlled catalytic interface and new insights into the role of TEOA in photochemical CO2 reduction.

3.
Inorg Chem ; 60(10): 7364-7371, 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-33891407

RESUMO

Photocatalytic carbon dioxide reduction (CO2RR) is considered to be a promising sustainable and clean approach to solve environmental issues. Polyoxometalates (POMs), with advantages in fast, reversible, and stepwise multiple-electron transfer without changing their structures, have been promising catalysts in various redox reactions. However, their performance is often restricted by poor thermal or chemical stability. In this work, two transition-metal-modified vanadoborate clusters, [Co(en)2]6[V12B18O54(OH)6]·17H2O (V12B18-Co) and [Ni(en)2]6[V12B18O54(OH)6]·17H2O (V12B18-Ni), are reported for photocatalytic CO2 reduction. V12B18-Co and V12B18-Ni can preserve their structures to 200 and 250 °C, respectively, and remain stable in polar organic solvents and a wide range of pH solutions. Under visible-light irradiation, CO2 can be converted into syngas and HCOO- with V12B18-Co or V12B18-Ni as catalysts. The total amount of gaseous products and liquid products for V12B18-Co is up to 9.5 and 0.168 mmol g-1 h-1. Comparing with V12B18-Co, the yield of CO for V12B18-Ni declines by 1.8-fold, while that of HCOO- increases by 35%. The AQY of V12B18-Co and V12B18-Ni is 1.1% and 0.93%, respectively. These values are higher than most of the reported POM materials under similar conditions. The density functional theory (DFT) calculations illuminate the active site of CO2RR and the reduction mechanism. This work provides new insights into the design of stable, high-performance, and low-cost photocatalysts for CO2 reduction.

4.
Anal Methods ; 13(9): 1147-1153, 2021 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-33576362

RESUMO

To evaluate the grain size and particle number formed in a non-equilibrium flow mixing state, flow-injection analysis (FIA) was combined with focused beam reflectance measurement (FBRM). The influence of BaCl2, PEG-4000, ethanol, flowrate, temperature and acidity on the dynamic formation of BaSO4 particles was evaluated. Optimization parameters obtained were 5% BaCl2 as the reagent, 2% PEG-4000 + 6% ethanol as the stabilizer and 0.3 mol L-1 HCl as the carrier with 4 ml min-1 flowrate, and the BaSO4 particle size distribution in the system was in the 1-50 µm range. Under optimized conditions, the system was successfully used for the determination of high sulfate concentrations in the wet-process phosphoric acid process in the 3.2-48 g L-1 (Sct = 55c + 208, r = 0.998, n = 3) range for SO42-. The relative standard deviation was less than 1.86% (n = 11), the detection limit was 0.95 g L-1, the sample throughput reached 30 samples per h, recovery data were within the 97-106% range, and the results were consistent with those of gravimetry (RD < 3%). The system avoids the large error caused by high dilution and the slow analysis speed when measuring high sulfate concentrations.

5.
ACS Appl Mater Interfaces ; 13(2): 2462-2471, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33411498

RESUMO

The rational design and construction of multifunctional electrocatalysts with high activity, low cost, and outstanding stability are highly desirable for the development of renewable energy but are still a big challenge. Bimetallic catalysts are a kind of promising candidates, like the hybrids of Co and VN nanoparticles (Co/VN). However, the inevitable aggregation during the preparation and electrochemical process lowers their reactivity and durability. Herein, small Co/VN nanoparticles (4-8 nm) embedded in porous graphitic carbon layers (Co/VN NPs@C) were obtained through the pyrolysis of metal-organic frameworks (MOFs). The synergistic effect of in situ generated Co and VN NPs together with fast electron transfer from graphitic carbon layers renders this catalyst to possess excellent trifunctional performance. More attractively, Co/VN NPs@C as both the anode and the cathode shows a low voltage of 1.58 V when the current density is up to 10 mA cm-2, exceeding most electrocatalysts based on non-noble metals. The rechargeable Zn-air batteries constructed by Co/VN NPs@C deliver high round-trip efficiency together with a peak power density of 130 mW cm-2, a specific capacity of 757 mAh g-1, and desirable stability, outperforming the traditional Zn-air batteries based on the Pt/C and RuO2 pair. This work opens a promising avenue toward constructing highly effective multifunctional electrocatalysts by designing small-sized nanoparticles with various active sites derived from MOFs.

6.
Chem Commun (Camb) ; 57(8): 1042-1045, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33409516

RESUMO

An unprecedented Mo-organic molecular cage built on interesting {MoVI2O5} secondary building blocks and BTC ligands, which has been successfully synthesized and systematically characterized, presents the first example of an isopolyoxomolybdates(vi)-organic molecular cage. An investigation into the related Cs+-exchange experiment was performed in detail.

7.
Nanotechnology ; 32(7): 075602, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33241790

RESUMO

The mercury ions in waste water have threatened public health and environmental protection. In this sense, novel materials with outstanding performances for removal of Hg2+ are imperative. Herein, we demonstrate a thiol-functionalized zirconium metal-organic cage (MOC-(SH)2) with excellent dispersion displays ideal properties for Hg2+ capture. MOC-(SH)2 exhibits the ability of removing Hg2+ in aqueous solutions with a capacity of 335.9 mgHg2+/gMOC-(SH)2, which surpasses that of classical Zr-based metal-organic framework Uio-66-(SH)2 by 1.89 folds. The higher loading capacity of MOC-(SH)2 is probably owing to the excellent dispersion of the discrete cage, which makes the accessibility of binding sites (thiol) easier. Additionally, 99.6% of Hg2+ can be effectively captured by MOC-(SH)2 with the concentration decreased from 5 to 0.02 ppm reaching the permissible limit for Hg2+, outperforming the performance of Uio-66-(SH)2. The excellent absorption property of MOC-(SH)2 is also achieved in terms of superior selectivity under the presence of competitive metal ions. Meanwhile, the regenerated MOC-(SH)2 can be reused without apparent loss of Hg2+ loading capacity. UV-vis absorption spectra, IR spectra and emission spectra further verified the strong chemical affinity between Hg2+ and the thiol of MOC-(SH)2. The study lays the groundwork for using Zr-MOCs in the removal of toxic metal ions and environmental sustainability.

8.
RSC Adv ; 11(61): 38814-38819, 2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-35493234

RESUMO

The remarkably reversible thermochromic luminescence behavior and the rare nonlinear optical (NLO) properties of the [Ag55(MoO4)6(C[triple bond, length as m-dash]C t Bu)24(CH3COO)18(CH3COO)]·2H2O ({Ag55Mo6} for short) nanocluster reported were investigated experimentally. The important contributions of Ag+, C[triple bond, length as m-dash]C- ions and MoO4 2- groups to the NLO properties were proved by further density functional theory (DFT) calculations.

9.
Chem Commun (Camb) ; 56(53): 7261-7264, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32469023

RESUMO

We prepare a novel COF for CO2 photoreduction with 99.9% CO selectivity in aqueous solution without a cocatalyst. DFT shows that the preferential adsorption of H+ on the COF results in increased CO2 adsorption energy providing an anchoring site of CO2, and with the cooperation of an ethylene group, CO2 reduction is triggered.

10.
Nanotechnology ; 31(25): 255402, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32143193

RESUMO

A system containing polyoxometalate ([Co-POM]2-) and [Ru(bpy)3]2+ as constructed for visible-light-induced CO2 conversion to syngas. In diluted CO2, high efficiency of 56.8 mmol g-1 h-1 in syngas production was gained, exceeding that of reported systems with [Ru(bpy)3]2+ participation in similar conditions. Mechanism studies revealed efficient photo-induced charge separation is achieved in the system and CO2 reduction tends to occur on [Ru(bpy)3]2+.

11.
Nanotechnology ; 31(21): 215605, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32018234

RESUMO

Halide perovskites have been employed as photocatalysts for CO2 photoreduction due to their excellent optical properties and unique electronic structure. However, their photocatalytic performance is relatively poor. Herein, we demonstrate a new strategy with Mn-doped CsPb(Br/Cl)3 mixed-halide perovskites as catalysts to enhance the efficiency of CO2 photoreduction. By tuning the content of Mn, a series of CsPb(Br/Cl)3:Mn perovskites are obtained and show high efficiency in CO2 conversion to CO and CH4. For the optimum catalyst sample, especially, the yields of CO and CH4 reach 1917 µmol g-1 and 82 µmol g-1 which are 14.2 and 1.4 times higher than those of CsPbBr3. This work provides new insights into improving the reactivity of perovskites in CO2 photoreduction.

12.
Chem Commun (Camb) ; 56(16): 2403-2406, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31994540

RESUMO

A nanosized Ta/W mixed addendum polyoxometalate (Cs12K3H7[MnTa18Si6W54O231]·61H2O) based on the unprecedented {MnTa18} cluster was fabricated successfully under hydrothermal conditions. An excellent electrochemical performance of this compound was found in lithium-ion batteries (LIBs) as an anode material. The discharge capacity was 829.9 mA h g-1 at a current density of 100 mA g-1 in the first cycle and stable at 428.4 mA h g-1 after 100 cycles, which suggests the potential application of this new compound in LIBs.

13.
Dalton Trans ; 49(6): 1747-1751, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-31967144

RESUMO

Two new cucurbit[6]uril (CB[6])-based metal-organic rotaxane networks (MORNs) were successfully obtained by tuning the coordination sphere of metal copper clusters. Compounds 1 and 2 exhibited relatively high proton conductivity at 85 °C and 97% relative humidity (RH), providing great promise for fuel cell electrolyte materials.

14.
FASEB J ; 34(2): 2524-2540, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31908026

RESUMO

The main mechanism of hyaluronidase 1(HYAL-1) in the development of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD) was unknown. In this study, a comprehensive inventory of pre-, intra-, and postoperative clinical and biological data of two cohorts (62 pancreatic cancer [PCa] and 111 pancreatic ductal adenocarcinoma [PDAC]) which could induce POPF were retrospectively analyzed. Then, a total of 7644 genes correlated with HYAL-1 was predicted in PDAC tissues and the enriched pathway, kinase targets and biological process of those correlated genes were evaluated. Finally, a mouse pancreatic fistula (PF) model was first built and in vitro studies were performed to investigate the effects of HYAL-1 on PF progression. Our data indicated that preoperative serum HYAL-1 level, pancreatic fibrosis score, and pancreatic duct size were valuable factors for detecting POPF of Grade B and C. The serum HYAL-1 level of 2.07 mg/ml and pancreatic fibrosis score of 2.5 were proposed as the cutoff values for indicating POPF. The bioinformatic analysis and in vitro and in vivo studies demonstrated that HYAL-1 facilitates pancreatic acinar cell autophagy via the dephosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) and signal transducers and activators of transcription 3 (STAT3) signaling pathways, which exacerbate pancreatic secretion and inflammation. In summary, the preoperative serum HYAL-1 was a significant predictor for POPF in patients who underwent PD. Tumor-induced HYAL-1 is one of core risk in accelerating PF and then promoting pancreatic secretion and acute inflammation response through the AMPK and STAT3-induced autophagy.


Assuntos
Autofagia/fisiologia , Hialuronoglucosaminidase/sangue , Fístula Pancreática/patologia , Pancreaticoduodenectomia , Adulto , Idoso , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/cirurgia , Feminino , Humanos , Intestinos/patologia , Masculino , Pessoa de Meia-Idade , Pâncreas/patologia , Fístula Pancreática/diagnóstico , Fístula Pancreática/cirurgia , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia/métodos , Estudos Retrospectivos , Fatores de Risco
15.
Chemistry ; 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31631411

RESUMO

Hybrid materials have obtained well-deserved attention for energy storage devices, because they show high capacitances and high energy densities induced by the synergistic effect between complementary components. Polyoxometalate-based metal-organic frameworks (POMOFs) possess the abundant redox-active sites and ordered structures of polyoxometalates (POMs) and metal-organic frameworks (MOFs), respectively. Here, an asymmetric supercapacitor (ASC) NENU-5/PPy/60//FeMo/C was fabricated in which both its electrodes are prepared from POMOF precursors. A typical POMOF material, NENU-5, was first connected with polypyrrole (PPy) through electrodeposition to form the cathode material NENU-5/PPy. Another representative POMOFs material, PMo12 @MIL-100, was carbonized to obtain the anode material FeMo/C. Cathode NENU-5/PPy exhibited an extraordinary capacitance of 508.62 F g-1 (areal capacitance: 2034.51 mF cm-2 ). In addition, anode FeMo/C shows excellent cyclic stability attributed to its unique structure. Finally, benefiting from the outstanding capacitances and structural merits of the anode and cathode, assembled asymmetric supercapacitor NENU-5/PPy/60//FeMo/C achieves an energy density of 1.12 mWh cm-3 at a power density output of 27.78 mW cm-3 , as well as a notable life of 10 000 cycles with an capacity retention of 80.62 %. Thus, the unique ASC is strongly competitive in high capacitance, long cycle life, and high energy-required energy storage devices.

16.
Inorg Chem ; 58(19): 12895-12904, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31532221

RESUMO

The reaction of mid-lanthanide (Ln) ions with the preformed {Se6W39} precursor under reasonably acidic aqueous conditions in the presence of organic amine cations results in an unprecedented nanoscale lanthanide-functionalized polyoxotungstate family, which are rare examples of mid-lanthanide-containing selenotungstates. (C4H10NO)9Na3[Dy3Se3.5W30O107.5(H2O)10]·22H2O (1) and (NH4)3(C2H8N)Na2[Dy4Se6W38O132(H2O)26(OH)6]·18H2O (2) reveal a trimeric Keggin assembly and a cyclic {Se6W38}-based chain, respectively, whereas (NH4)4Na8[Gd4Se6W48O166(H2O)20(OH)4]·21H2O (3) and (NH4)9(C2H8N)4Na5[Ln6Se6W58O202(H2O)20(OH)4]·58H2O (4; Ln = Gd, Tb, or Dy) are a few examples of polyoxometalates consisting of both classical Keggin and Wells-Dawson building blocks, and (NH4)4(C2H8N)5Na13[Ln4Se8W56O196(H2O)x(OH)10]·40H2O (5; Ln = Gd, Tb, or Dy; x = 12 for Gd and Tb and 10 for Dy) features the largest "pure" Wells-Dawson selenotungstate {Se8W56} bearing a length of 3.73 nm. A library of Se-templated species involving the first reported Keggin {α-SeW8} and Wells-Dawson {α-Se2W16} building blocks as well as some decisive assembly factors during the synthesis is responsible for these architectures. All of the compounds were structurally characterized in the solid and solution by single-crystal X-ray diffraction, IR, thermogravimetric-differential thermal analysis, and electrospray ionization mass spectrometry. Magnetic properties indicate that 1 and 4-Dy show probable single-molecule-magnet behavior with obvious frequency dependence, whereas 3 and 4-Gd present the antiferromagnetic interactions between the GdIII centers.

17.
Chem Commun (Camb) ; 55(82): 12328-12331, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31556436

RESUMO

A newly prepared tetraphenylethylene-based (TPE-based) covalent organic polymer (COP) named COP-1 exhibits high selectivity for sensing Fe3+ and the limit of detection (LOD) for Fe3+ is 0.42 µM, which is lower than the reported metal-free porous polymers. Furthermore, a WLED is fabricated and the CIE coordinates are (0.32, 0.33), very close to pure white light. The COP-1 shows potential applications in biosensors of Fe3+ and preparation of WLEDs.

18.
Dalton Trans ; 48(27): 9939-9943, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31204763

RESUMO

Three new high-dimensional cucurbit[6]-based metal-organic rotaxane frameworks [Co2(PR43)(BDC)2Cl2]·4H2O (1), [Co2(PR43)(BTC)2]·6H2O (2) and [Co2(PR43)(BPT)2]·20H2O (3) were obtained via the hydrothermal synthesis method. Compound 1 comprised a two-dimensional layered structure, while compounds 2 and 3 exhibited three-dimensional pillared structures. All the compounds showed good thermal stabilities. Furthermore, the magnetic properties of compounds 1-3 were also investigated in detail.

19.
Phytochemistry ; 162: 199-206, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30947089

RESUMO

Twelve previously undescribed phenolic meroterpenoids, cochlearols N-Y, along with two known analogs, ganocochlearins B and C, were isolated from the fruiting bodies of Ganoderma cochlear. Most of these substances were isolated as racemic mixtures. The structures of cochlearols N-Y were assigned based upon spectroscopic data and theoretical calculations. The renoprotective activities of these compounds were evaluated using normal and diseased rat renal interstitial fibroblast cells (NRK-49F). The results show that ganocochlearins S, U, X and Y display potent inhibitory activities against fibronectin overproduction in TGF-ß1-induced NRK-49F cells.


Assuntos
Citoproteção/efeitos dos fármacos , Ganoderma/química , Rim/citologia , Fenóis/química , Terpenos/química , Terpenos/farmacologia , Animais , Linhagem Celular , Carpóforos/química , Rim/efeitos dos fármacos , Modelos Moleculares , Conformação Molecular , Ratos
20.
Chem Soc Rev ; 48(1): 260-284, 2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-30451261

RESUMO

Dye-sensitized solar cells (DSSCs) are the third generation of photovoltaic cells developed by Grätzel and O'Regan. They have the characteristics of low cost, simple manufacturing process, tunable optical properties, and higher photoelectric conversion efficiency (PCE). With an ever increasing energy crisis, there is an urgent need to develop highly efficient, environmentally benign, and energy-saving cell materials. Polyoxometalates (POMs), a kind of molecular inorganic quasi-semiconductor, are promising candidates for use in different parts of DSSCs due to their excellent photosensitivity, redox, and catalytic properties, as well as their relative stability. Following a brief introduction to the development of DSSCs and the potential virtues of POMs in DSSCs, we attempt to make some generalizations about the energy level regulation of POMs that is the underlying theoretical basis for their application in DSSCs, and then we summarize the research progress of POMs in DSSCs in recent years. This is organized in terms of the properties of POMs, namely, electron acceptor, photosensitivity, redox and catalysis, based on the accumulation of our research into POMs over many years. Meanwhile, in view of the fact that the properties of POMs depend primarily on their electronic structural diversity, we keep this point in mind throughout the article with a view to revealing their structure-property relationships. Finally we provide a short summary and remarks on the future outlook. This review may be of interest to synthetic chemists devoted to designing POMs with specific structures, and researchers engaged in the extension of POMs to photoelectric materials.

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