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oe1(光电查) - 科学论文

594 条数据
?? 中文(中国)
  • Ultrafast synthesis of gold nanosphere cluster coated by graphene quantum dot for active targeting PA/CT imaging and near-infrared laser/pH-triggered chemo-photothermal synergistic tumor therapy

    摘要: In this work, simple raw materials and reaction conditions were used to synthesize a versatile nanoprobe using a one-step method. Graphene quantum dot (GQD) and gold chloride were mixed and irradiated with ultra-violet (UV) radiation for 1 min. Then, the gold nanosphere cluster with the diameter of 50 nm and coated using GQD was formed using a facile one-step approach. GQD played the roles of reducing agent, stabilizer and drug carrier instead of a harmful reducing agent or stabilizer. The nanoprobe had good dispersion, stability, excellent photoacoustic imaging (PAI) and computed tomography (CT) imaging performance, low cytotoxicity and photothermal conversion e?ciency of up to 51.31%. The results for cell and animal experiments showed that targeted PAI/CT imaging of tumor after modi?cation of folic acid (FA) could be obtained using the probe. Meanwhile, after the adsorption of doxorubicin, the chemo-photothermal combined therapy for tumor could be carried out through controlled drug release from GQD under heated and acidic environment of tumor. Additionally, the treatment e?ect was signi?cantly superior to single modes. The body weight, Hematoxylin and Eeosin (H&E) staining of main organs and blood biochemical indicators showed that the probe had good biological safety after injection. The current work proposes a new dual-mode bio-imaging and chemo-photothermal combined therapy nanoprobe, which presents good application prospect for tumor theragnostic.

    关键词: CT imaging,One-step synthesis,Drug release,Photoacoustic imaging,Chemo-photothermal therapy

    更新于2025-11-25 10:30:42

  • A supramolecular Cd( <scp>ii</scp> )-metallogel: an efficient semiconductive electronic device

    摘要: A sonication-based strategy for the synthesis of a functional supramolecular Cd(II)-metallogel (CdA-OX) has been achieved through mixing cadmium(II) acetate dihydrate and oxalic acid dihydrate, a low molecular weight gelator (LMWG), in N,N-dimethyl formamide solvent at room temperature under atmospheric pressure. The mechanical properties of the supramolecular Cd(II)-metallogel were investigated through a rheological study. The pebble-like self-assembly hierarchical architecture of the supramolecular metallohydrogel was visualized through field emission scanning electron microscopy investigations. The electrical properties of the metallogel were thoroughly examined and indicate its semiconducting nature. Based on its conducting properties, the Cd(II)-metallogel was successfully applied to a Schottky barrier diode. Overall, this work is a novel instance of technologically challenging electronic device application of a Cd(II)-metallogel.

    关键词: Schottky barrier diode,supramolecular Cd(II)-metallogel,sonication-based synthesis,electronic device,semiconducting nature

    更新于2025-11-21 11:18:25

  • Efficiency and Quality Issues in the Production of Black Phosphorus by Mechanochemical Synthesis: A Multi-Technique Approach

    摘要: Black phosphorus (BP) is a two-dimensional material potentially of great interest for applications in the fields of energy, sensing, and microelectronics. One of the most interesting methods to obtain BP is the conversion from red phosphorus (RP) by means of high-energy mechanochemical synthesis. To date, however, this synthesis process was not well characterized. In this work, starting from the mathematical model of energy transfer during the ball milling process, we investigate the effects on RP → BP conversion of three experimental parameters, the rotation speed, the milling time, and the weight ratio between the spheres and the milled material (BtPw ratio). The efficiency of the conversion process was verified by solid-state NMR, Raman spectroscopy, and X-ray diffraction. Whereas the first two parameters have a minor importance, the BtPw ratio plays a primary role in the RP → BP conversion. Yields approaching 100% can be obtained also with short milling times (15 min) and adequate rotation speed (e.g., 500 r.p.m.), provided that the BtPw ratio >40:1 is used. These results confirm the energy sustainability of the mechanochemical synthesis approach.

    关键词: diffraction,solid-state NMR,anode,post-lithium ion batteries,Raman,mechanochemical synthesis

    更新于2025-11-21 11:18:25

  • Nanoparticles for Bioapplications: Study of the Cytotoxicity of Water Dispersible CdSe(S) and CdSe(S)/ZnO Quantum Dots

    摘要: Semiconductor nanocrystals or quantum dots (QDs) have unique optical and physical properties that make them potential imaging tools in biological and medical applications. However, concerns over the aqueous dispersivity, toxicity to cells, and stability in biological environments may limit the use of QDs in such applications. Here, we report an investigation into the cytotoxicity of aqueous dispersed CdSe(S) and CdSe(S)/ZnO core/shell QDs in the presence of human colorectal carcinoma cells (HCT-116) and a human skin fibroblast cell line (WS1). The cytotoxicity of the precursor solutions used in the synthesis of the CdSe(S) QDs was also determined in the presence of HCT-116 cells. CdSe(S) QDs were found to have a low toxicity at concentrations up to 100 μg/mL, with a decreased cell viability at higher concentrations, indicating a highly dose-dependent response. Meanwhile, CdSe(S)/ZnO core/shell QDs exhibited lower toxicity than uncoated QDs at higher concentrations. Confocal microscopy images of HCT-116 cells after incubation with CdSe(S) and CdSe(S)/ZnO QDs showed that the cells were stable in aqueous concentrations of 100 μg of QDs per mL, with no sign of cell necrosis, confirming the cytotoxicity data.

    关键词: core/shell QDs,HCT-116,water dispersive QDs,WS1,bioapplications of QDs,aqueous synthesis,in vitro cytotoxicity of QDs

    更新于2025-11-21 11:08:12

  • Hydrogen Induced Etching Features of Wrinkled Graphene Domains

    摘要: Wrinkles are observed commonly in CVD (chemical vapor deposition)-grown graphene on Cu and hydrogen etching is of significant interest to understand the growth details, as well as a practical tool for fabricating functional graphene nanostructures. Here, we demonstrate a special hydrogen etching phenomenon of wrinkled graphene domains. We investigated the wrinkling of graphene domains under fast cooling conditions and the results indicated that wrinkles in the monolayer area formed more easily compared to the multilayer area (≥two layers), and the boundary of the multilayer area tended to be a high density wrinkle zone in those graphene domains, with a small portion of multilayer area in the center. Due to the site-selective adsorption of atomic hydrogen on wrinkled regions, the boundary of the multilayer area became a new initial point for the etching process, aside from the domain edge and random defect sites, as reported before, leading to the separation of the monolayer and multilayer area over time. A schematic model was drawn to illustrate how the etching of wrinkled graphene was generated and propagated. This work may provide valuable guidance for the design and growth of nanostructures based on wrinkled graphene.

    关键词: graphene,hydrogen etching,wrinkling,CVD synthesis

    更新于2025-11-21 11:01:37

  • Molten salt synthesis of highly ordered and nanostructured hexagonal boron nitride

    摘要: Hexagonal boron nitride (h-BN) is a well-known ceramic that has wide application areas ranging from electronics to metallurgy. However, highly ordered h-BN is conventionally synthesized at high temperatures above 1800 °C. In this work, we investigated the formation of BN from boric acid (H3BO3)-ammonium chloride (NH4Cl) mixture in the sodium chloride (NaCl)-potassium chloride (KCl) eutectic salt. We report the synthesis of highly ordered and nanostructured h-BN at 1000 °C using molten salt synthesis. The effect of starting composition, synthesis temperature, and dwell time on BN formation and its structural ordering were systematically investigated. It is concluded that the molten salt plays important roles in the formation of BN and its structural ordering, which is achieved by i) decomposing the boron (B)-nitrogen (N) bearing reactants that lead to the formation of BN layers, and ii) increasing the mobility of BN layers formed. Furthermore, we propose a possible reaction mechanism that governs the BN formation from the reactant mixture in molten salts and explain the observations based on thermodynamic and kinetic considerations.

    关键词: Molten salt synthesis,NaCl-KCl eutectic salt,Boron nitride,Structural ordering,High-resolution transmission electron microscopy

    更新于2025-11-21 11:01:37

  • Electrochemical synthesis of Zn: ZnO/Ni2P and efficient photocatalytic degradation of Auramine O in aqueous solution under multi-variable experimental design optimization

    摘要: Present work is devoted to synthesis Zn: ZnO/Ni2P by electrochemical method and identification and properties investigation by various techniques such as SEM, EDS, XRD and DRS. The experimental results reveal have ability for degradation of Auramine O (AO) following estimation of correlation among response to (main effect and variables interactions) variable like irradiation time, nanocomposite mass, pH and initial AO concentrations by a central composite design (CCD). The optimum condition for the photo-degradation of AO by photocatalyst was 6.72, 61.66 min, 13.13 mg.L-1 and 0.014 g correspond to the pH, irradiation time, AO concentration and photocatalyst mass, respectively. At these optimum conditions, the AO photocatalytic degradation percentages with desirability of 0.94 was 95.47% using reasonable consumption of reagent. The quasi first-order kinetic model derived from Langmuir–Hinshelwood (L–H) efficiently represent real behavior of experimental data of correspond to under study system. The photocatalytic reaction, L–H rate constants and L–H adsorption constants for Zn: ZnO/Ni2P were 0.0375 min-1, 27.39 mg.min-1.L and 0.00048 L.mg-1, respectively.

    关键词: photocatalytic degradation,Auremine O,electrochemical synthesis.,Zn: ZnO/Ni2P,response surface methodology

    更新于2025-11-21 11:01:37

  • Steady Enhancement in Photovoltaic Properties of Fluorine Functionalized Quinoxaline-Based Narrow Bandgap Polymer

    摘要: To investigate the influence of fluoride phenyl side-chains onto a quinoxaline (Qx) unit on the photovoltaic performance of the narrow bandgap (NBG) photovoltaic polymers, herein, two novel NBG copolymers, PBDTT-DTQx and PBDTT-DTmFQx, were synthesized and characterized. 2-ethylhexylthiothiophene-substituted benzodithiophene (BDTT), 2,3-diphenylquinoxaline (DQx) [or 2,3-bis(3-fluorophenyl)quinoxaline (DmFQx)] and 2-ethylhexylthiophene (T) were used as the electron donor (D) unit, electron-withdrawing acceptor (A) unit and π-bridge, respectively. Compared to non-fluorine substituted PBDTT-DTQx, fluoride PBDTT-DTmFQx exhibited a wide UV-Vis absorption spectrum and high hole mobility. An enhanced short-circuit current (Jsc) and fill factor (FF) simultaneously gave rise to favorable efficiencies in the polymer/PC71BM-based polymer solar cells (PSCs). Under the illumination of AM 1.5G (100 mW cm?2), a maximum power conversion efficiency (PCE) of 6.40% was achieved with an open-circuit voltage (Voc) of 0.87 V, a Jsc of 12.0 mA cm?2 and a FF of 61.45% in PBDTT-DTmFQx/PC71BM-based PSCs, while PBDTT-DTQx-based devices also exhibited a PCE of 5.43%. The excellent results obtained demonstrate that PBDTT-DTmFQx by fluorine atom engineering could be a promising candidate for organic photovoltaics.

    关键词: quinoxaline,synthesis,polymer solar cells,bulk heterojunction,narrow bandgap conjugated polymer

    更新于2025-11-19 16:56:42

  • Photoluminescence enhancement <i>via</i> microwave irradiation of carbon quantum dots derived from solvothermal synthesis of <scp>l</scp> -arginine

    摘要: Photoluminescence enhancement of carbon quantum dots was achieved via solvothermal synthesis followed by microwave irradiation. Nitrogen and phosphorous doped carbon quantum dots were prepared by solvothermal heating of L-arginine with phosphoric acid for 12 hours followed by microwave irradiation for 3 minutes. The photoluminescence enhancement was nearly two fold after microwave irradiation. The morphology, structure, and surface properties were the same for the solvothermal (CQDs-S) as well as after microwave (CQDs-M) irradiation. Thus, the enhancement is attributed to the decrease of surface defects within CQDs, which led to a decrease in the non-radiative transitions. The CQDs were quenched selectively by Fe3+ ions. The quenching led to the fabrication of the fluorescence probe for ferric ion determination. The CQDs-M had a low detection limit of 4.0 nM, while CQDs-S had a limit of 50 nM. This study gives a tool for enhancing photoluminescence quantum yields, which is highly desired for biosensing and bioimaging applications.

    关键词: Photoluminescence enhancement,Fluorescence probe,Solvothermal synthesis,Ferric ion determination,Microwave irradiation,Carbon quantum dots

    更新于2025-11-19 16:56:42

  • Band gap engineered zinc oxide nanostructures <i>via</i> a sol–gel synthesis of solvent driven shape-controlled crystal growth

    摘要: A reliable sol–gel approach, which combines the formation of ZnO nanocrystals and a solvent driven, low shape-controlled, crystal-growth process to form well-organized ZnO nanostructures at temperature is presented. The sol of ZnO nanocrystals showed shape-controlled crystal growth with respect to the solvent type, resulting in either nanorods, nanoparticles, or nanoslates. The solvothermal process, along with the solvent polarity facilitate the shape-controlled crystal growth process, augmenting the concept of a selective adhesion of solvents onto crystal facets and controlling the final shape of the nanostructures. The XRD traces and XPS spectra support the concept of selective adhesion of solvents onto crystal facets that leads to yield different ZnO morphologies. The shift in optical absorption maxima from 332 nm in initial precursor solution, to 347 nm for ZnO nanocrystals sol, and finally to 375 nm for ZnO nanorods, evidenced the gradual growth and ripening of nanocrystals to dimensional nanostructures. The engineered optical band gaps of ZnO nanostructures are found to be ranged from 3.10 eV to 3.37 eV with respect to the ZnO nanostructures formed in different solvent systems. The theoretical band gaps computed from the experimental XRD spectral traces lie within the range of the optical band gaps obtained from UV-visible spectra of ZnO nanostructures. The spin-casted thin film of ZnO nanorods prepared in DMF exhibits the electrical conductivity of 1.14 × 10?3 S cm?1, which is nearly one order of magnitude higher than the electrical conductivity of ZnO nanoparticles formed in hydroquinone and ZnO sols. The possibility of engineering the band gap and electrical properties of ZnO at nanoscale utilizing an aqueous-based wet chemical synthesis process presented here is simple, versatile, and environmentally friendly, and thus may applicable for making other types of band-gap engineered metal oxide nanostructures with shape-controlled morphologies and optoelectrical properties.

    关键词: electrical conductivity,ZnO nanostructures,optical band gap,shape-controlled crystal growth,sol–gel synthesis

    更新于2025-11-19 16:56:42