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1.
J Colloid Interface Sci ; 669: 175-189, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38713956

RESUMO

In this study, AgBr/Bi4Ti3O12/Bi2Sn2O7 (ABr/BTO/BSO) composites were successfully synthesized to facilitate multi-channel fast charge transfer. This directs the charge carriers to travel along multichannel pathways and suppresses carrier recombination. The mechanisms underlying charge transfer in the dual S-scheme heterojunction composites were elucidated using density functional theory (DFT) and in situ irradiated X-ray photoelectron spectroscopy (ISI-XPS). Furthermore, electron spin resonance (ESR) and burst experiments verified h+, ·O2 -, and ·OH as the primary active species in the catalytic process. The ABr/BTO/BSO composites demonstrated exceptional photocatalytic redox capabilities, completely degrading rhodamine B (RhB) and achieving degradation rates of 77.21% for tetracycline (TC) and 81.04% for Cr (VI). Both experimental and theoretical analyses confirmed the intrinsic efficacy of photo-induced electron movement within the composites. This research introduces innovative design concepts and strategies for the advanced exploration of electron channel transfer in ABr/BTO/BSO ternary composites and the development of novel composite photocatalytic systems.

2.
Sci Total Environ ; 925: 171656, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38490416

RESUMO

Toxic metal(loid)s contamination of paddy soil is a nonnegligible issue and threatens food safety considering that it is transmitted via the soil-plant system. Applying remediation agents could effectively inhibit the soil available toxic metal(loid)s and reduce their accumulation in rice. To comprehensively quantify how remediation agents impact the accumulation of Cd/Pb/As in rice, rice growth and yield, the accumulation of available Cd/Pb/As in paddy soil, and soil characteristics, 50 peer-reviewed publications were selected for meta-analysis. Overall, the application of remediation agents exhibited significant positive effects on rice plant length (ES = 0.05, CI = 0.01-0.08), yield (ES = 0.20, CI = 0.13-0.27), peroxidase (ES = 0.56, CI = 0.18-0.31), photosynthetic rate (ES = 0.47, CI = 0.34-0.61), and respiration rate (ES = 0.68, CI = 0.47-0.88). Among the different types of remediation agents, biochar was the most effective in controlling the accumulation of Cd/Pb/As in all portions of rice, and was also superior in inhibiting the accumulation of Pb in rice grains (ES = -0.59, 95 % CI = -1.04-0.13). This study offers an essential contribution for the remediation strategies of toxic metal(loid)s contaminated paddy fields.


Assuntos
Oryza , Poluentes do Solo , Solo , Cádmio/análise , Chumbo , Poluentes do Solo/análise
4.
Angew Chem Int Ed Engl ; 62(48): e202313784, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37819255

RESUMO

Infrared light driven photocatalytic reduction of atmospheric CO2 is challenging due to the ultralow concentration of CO2 (0.04 %) and the low energy of infrared light. Herein, we develop a metallic nickel-based metal-organic framework loaded with Pt (Pt/Ni-MOF), which shows excellent activity for thermal-photocatalytic conversion of atmospheric CO2 with H2 even under infrared light irradiation. The open Ni sites are beneficial to capture and activate atmospheric CO2 , while the photogenerated electrons dominate H2 dissociation on the Pt sites. Simultaneously, thermal energy results in spilling of the dissociated H2 to Ni sites, where the adsorbed CO2 is thermally reduced to CO and CH4 . The synergistic interplay of dual-active-sites renders Pt/Ni-MOF a record efficiency of 9.57 % at 940 nm for converting atmospheric CO2 , enables the procurement of CO2 to be independent of the emission sources, and improves the energy efficiency for trace CO2 conversion by eliminating the capture media regeneration and molecular CO2 release.

5.
Nat Commun ; 14(1): 4243, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37454112

RESUMO

A carbene-catalyzed chemoselective reaction of unsymmetric enedials is disclosed. The reaction provides a concise access to bicyclic furo[2,3-b]pyrroles derivatives in excellent selectivity. A main challenge in this reaction is chemoselective reaction of the two aldehyde moieties in the enedial substrates. Mechanistic studies via experiments suggest that our chemoselectivity controls are mostly achieved on the reducing properties of different sited Breslow intermediates. Several side reactions processes and the corresponding side adducts are also studied by high resolution mass spectroscopy analysis. Our method allows for efficient assembly of the furo[2,3-b]pyrrole structural moieties and their analogues widely found in natural products and pharmaceuticals.


Assuntos
Metano , Pirróis , Estrutura Molecular , Pirróis/química , Metano/química , Catálise
6.
Artigo em Inglês | MEDLINE | ID: mdl-35776818

RESUMO

In this article, we propose a multiscale cross-connected dehazing network with scene depth fusion. We focus on the correlation between a hazy image and the corresponding depth image. The model encodes and decodes the hazy image and the depth image separately and includes cross connections at the decoding end to directly generate a clean image in an end-to-end manner. Specifically, we first construct an input pyramid to obtain the receptive fields of the depth image and the hazy image at multiple levels. Then, we add the features of the corresponding dimensions in the input pyramid to the encoder. Finally, the two paths of the decoder are cross-connected. In addition, the proposed model uses wavelet pooling and residual channel attention modules (RCAMs) as components. A series of ablation experiments shows that the wavelet pooling and RCAMs effectively improve the performance of the model. We conducted extensive experiments on multiple dehazing datasets, and the results show that the model is superior to other advanced methods in terms of peak signal-to-noise ratio (PSNR), structural similarity (SSIM), and subjective visual effects. The source code and supplementary are available at https://github.com/CCECfgd/MSCDN-master.

7.
Dalton Trans ; 50(43): 15602-15611, 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34668504

RESUMO

A novel solid-state Z-scheme photocatalyst Ag3PO4/CSs/AgBr (carbon spheres, CSs) was rationally designed and successfully synthesized via a facile hydrothermal coprecipitation reaction. AgBr and Ag3PO4 were effectively loaded on the surface of the CSs and Ag3PO4/CSs/AgBr showed wide visible light absorption and superior photocatalytic performance. On the basis of ultraviolet photoelectron spectroscopy (UPS) analysis and scavenger reactions, a possible photocatalytic reaction mechanism for Ag3PO4/CSs/AgBr is proposed. The CSs act as a charge carrier transfer bridge for constructing the all-solid-state Z-scheme photocatalyst. The photogenerated electrons from Ag3PO4 and holes from AgBr congregate and recombine in the CSs phase, leaving photogenerated electrons with strong reduction abilities in the conduction band (CB) of AgBr and holes with strong oxidation abilities in the valence band (VB) of Ag3PO4. Some Ag+ ions accept electrons and turn to Ag nanoparticles (NPs), leading to the surface plasmon resonance of Ag NPs on AgBr. Therefore, the photocatalytic performance and stability were significantly improved.

8.
Dalton Trans ; 50(37): 13112-13123, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34581346

RESUMO

Mn4+-activated oxide red phosphors are always a hot topic in the luminescent material field to solve the lack of red light components in white-light-emitting diodes (WLEDs). Herein, a series of novel deep red-emitting CaAl12-mPmO19+m:0.01Mn4+,0.2Mg2+ (m = 0-0.15) phosphors were synthesized and their crystal structure, luminescence properties and thermal stability were investigated in detail. The high-valence P5+ is used to replace low-valence Al3+ in the luminescent host CaAl12O19 to improve the photoluminescence quantum yield (PLQY) of phosphors. The doping of P5+ does not change the crystal phase structure of phosphors, and the luminescence intensity and PLQY are significantly enhanced. The analysis of the photocurrent and fluorescence lifetime shows that an electron trap with a quantum-confinement structure is formed in the phosphor host, which plays a key role in buffering photogenerated electrons. Therefore, the PLQY of the P5+-doped CaAl11.90P0.1O19.10:0.01Mn4+,0.2Mg2+ phosphor increased from 9.8% (P5+-undoped) to 70.2%, and the mechanism of PLQY enhancement is proposed based on the analysis of the crystal structure. Furthermore, the phosphor has superior thermal stability and color purity (96.8%). Overall, this work provides new insights and ideas on quantum confinement effects for improving the quantum yield of Mn4+-activated luminescent materials.

9.
Colloids Surf B Biointerfaces ; 195: 111264, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32707431

RESUMO

The quercetin loaded Eudragit L-100 nanofiber membrane with high ductility and a desired drug release rate was prepared in this work. The morphological characteristics of the Eudragit L-100 nanofibers with different drug loadings amount were observed by scanning electron microscope (SEM). After adding Polyethylene glycol-4000 (PEG-4000), the degree of the fiber breakage decreased and the fiber length increased. Fiber diameter analysis, X-ray diffraction (XRD), thermal analysis (TA) and differential scanning calorimetry (DSC) have demonstrated that the crystallinity of the fiber membrane was significantly reduced after adding PEG-4000. The mechanical property test also showed that the fiber membrane with PEG-4000 had a greater elongation at break. The in vitro release experiments showed that after adding PEG-4000, the drug-loaded fibers showed rapid release at a pH of 7.4. After adopting the strategy of reducing the crystallinity, the ductility of the fiber was enhanced, which could provide a fesibility to enable this nanofiber membrane to be used in sports wound healing treatment. The electrospun Eudragit L-100 nanofiber membranes loaded with quercetin have the potential to be applied in sport wound healing of skin, tissue and joints.


Assuntos
Nanofibras , Liberação Controlada de Fármacos , Ácidos Polimetacrílicos , Quercetina
10.
R Soc Open Sci ; 5(9): 180134, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30839690

RESUMO

Polylactic electrospun porous fibres have been widely used in tissue engineering scaffolds. However, the application of linear polylactic is limited due to its poor hydrophilicity, which leads to phase separation and has been seldom used in porous fibre preparation. Instead, branching polylactic acts as a new effective method to prepare porous fibres because it can increase polylactic polar property and make it easy to be formulated in the following application. In the current study, we prepared an ultra-high molecular weight of high branching polylactic with glycerol as the initiator by controlling the ring-opening polymerization time, adding amount of catalyst and glycerol. The structure, molecular weight and thermal properties of copolymers were tested subsequently. The result showed that the surface of the high branching polylactic films is smooth, hydrophilic and porous. This branching polylactic formed electrospun porous fibres and possessed a strong adsorption of silver ion. Our study provided a simple and efficient way to synthesize branching polylactic polymer and prepare electrospun porous fibres, which may provide potential applications in the field of biomaterials for tissue engineering or antibacterial dressing compared with the application of linear polylactic and 3-arm polylactic materials.

11.
Nanoscale Res Lett ; 9(1): 558, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25328504

RESUMO

In this paper, we investigated the functional imaging properties of magnetic microspheres composed of magnetic core and CdTe quantum dots in the silica shell functionalized with folic acid (FA). The preparation procedure included the preparation of chitosan-coated Fe3O4 nanoparticles (CS-coated Fe3O4 NPs) prepared by a one-pot solvothermal method, the reaction between carboxylic and amino groups under activation of NHS and EDC in order to obtain the CdTe-CS-coated Fe3O4 NPs, and finally the growth of SiO2 shell vent the photoluminescence (PL) quenching via a Stöber method (Fe3O4-CdTe@SiO2). Moreover, in order to have a specific targeting capacity, the magnetic and fluorescent bifunctional microspheres were synthesized by bonding of SiO2 shell with FA molecules via amide reaction (Fe3O4-CdTe@SiO2-FA). The morphology, size, chemical components, and magnetic property of as-prepared composite nanoparticles were characterized by ultraviolet-visible spectroscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning transmission electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM), respectively. The results show that the magnetic and fluorescent bifunctional microspheres have strong luminescent which will be employed for immuno-labeling and fluorescent imaging of HeLa cells.

12.
Nanoscale Res Lett ; 9(1): 296, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24994954

RESUMO

Preparation of magnetic nanoparticles coated with chitosan (CS-coated Fe3O4 NPs) in one step by the solvothermal method in the presence of different amounts of added chitosan is reported here. The magnetic property of the obtained magnetic composite nanoparticles was confirmed by X-ray diffraction (XRD) and magnetic measurements (VSM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allowed the identification of spherical nanoparticles with about 150 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy (FTIR) demonstrated that CS-coated Fe3O4 NPs were obtained. Chitosan content in the obtained nanocomposites was estimated by thermogravimetric analysis (TGA). The adsorption properties of the CS-coated Fe3O4 NPs for bovine serum albumin (BSA) were investigated under different concentrations of BSA. Compared with naked Fe3O4 nanoparticles, the CS-coated Fe3O4 NPs showed a higher BSA adsorption capacity (96.5 mg/g) and a fast adsorption rate (45 min) in aqueous solutions. This work demonstrates that the prepared magnetic nanoparticles have promising applications in enzyme and protein immobilization.

13.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 11): o2126, 2008 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-21580988

RESUMO

The title compound, C(15)H(10)N(2), crystallizes with two independent mol-ecules in the asymmetric unit. The two benzene rings make dihedral angles of 60.32 (2) and 61.35 (3)°. The crystal packing is stabilized by weak π-π stacking inter-actions [centroid-to-centroid distances = 3.673 (4) and 3.793 (4) Å].

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