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oe1(光电查) - 科学论文

117 条数据
?? 中文(中国)
  • Fracto-mechanoluminescence in Mn/Cu doped ZnS induced by steel ball and cylindrical piston

    摘要: Herein, we present a comparison of fracto-mechanoluminescence (FML) from ZnS: Mn and ZnS:Cu phosphors prepared by solid state reaction (SSR) route. The FML emitted by two phosphors was compared in terms of its dependence on time and velocity. The FML intensity initially increases with time attains a peak value followed by decrease at still longer times. Peak ML intensities in both the cases are found to linearly increase with impact velocity and total ML intensity linearly increases with mass of the phosphor samples. ML and photoluminescence (PL) spectra of ZnS: Mn and ZnS: Cu phosphors are recorded to lie at 540 nm and 580 nm, respectively.

    关键词: Sensor,ZnS: Cu,ZnS: Mn,Mechanoluminescence,Phosphors

    更新于2025-11-21 11:18:25

  • Microwave-Assisted Synthesis of Quasi-Pyramidal CuInS <sub/>2</sub> -ZnS Nanocrystals for Enhanced Near-Infrared Targeted Fluorescent Imaging of Subcutaneous Melanoma

    摘要: Near-infrared (NIR) fluorescent CuInS2–ZnS nanocrystals (CIZS NCs) are synthesized via an ultra-fast, non-injection microwave (MW)-assisted nanoalloying process at 230 oC within 5 min using 1-dodecanethiol (DDT) as both the sulfur source and solvent under solvothermal (ST) condition. The structural and surface analyses reveal that DDT-functionalized CIZS NCs exhibit quasi-pyramids of tetragonal-phase with well-defined facets. The DDT-functionalized CIZS NCs present a photoluminescence quantum yield (PLQY) of 76% and a long-lived fluorescence lifetime of ≈0.6 μs in organic-phase. Subsequently, DDT-functionalized CIZS NCs are phase-transferred via ligand-exchange using 11-mercaptoundecanoic acid (MUA) into water-soluble MUA–CIZS NCs that exhibit a substantial PLQY of 55%. In addition, the NIR-fluorescent MUA-functionalized CIZS NCs in conjugation with folic acid (FA), as a tumor-targeting ligand, demonstrates enhanced tumor-targeted imaging ability. The FA–MUA–CIZS NC conjugates exhibit a cell viability of ≈75% even at the highest concentration of 1 mg mL–1 and a labeling efficiency of 95.4%. The in vivo imaging results corroborate that FA–MUA–CIZS NCs conjugates are actively targeted to folate receptor-positive B16F10 tumor-bearing C57BL/6 mice in 2 h. The histopathological and hematological studies confirm no significant changes in tissue architecture and blood biochemical parameters. The confocal microscopy studies reveal deep penetration and uniform distribution of FA–MUA–CIZS NCs conjugates in subcutaneous melanoma.

    关键词: CuInS2–ZnS nanocrystals,nano-bioprobe,nanoalloying approach,targeted bioimaging,microwave-solvothermal method

    更新于2025-11-21 11:08:12

  • Probing the Role of Nickle Dopant in Aqueous Colloidal ZnS Nanocrystals for Efficient Solar-Driven CO2 Reduction

    摘要: Photocatalytic CO2 reduction reaction (CO2RR) on a heterogeneous catalyst offers the possibility for CO2 abatement and emerges as a promising avenue for renewable carbonaceous fuels production at ambient temperature and pressure using solar light as the sole energy input. Here, we report a newly aqueous colloidal comprised of monodispersed Ni-doped ZnS (ZnS:Ni) nanocrystals as excellent visible-light-responsive photocatalysts for CO2RR into formate. The wavelength-dependent quantum yield shows a significant contribution of Ni doping for visible light absorption. A high selectivity (>95%) of HCOOH production and a remarkable quantum efficiency of 59.1% at 340 nm and 5.6 % at 420 nm are obtained over ZnS:Ni (0.1 %) colloidal nanocrystals modified by Cd2+. The abundant sulfur vacancies and extended visible light absorption of the constructed colloidal ZnS:Ni nanocrystals contribute to the prominent performance for CO2RR. However, excessive doping of Ni does not guarantee an increase of photocatalytic CO2RR due to a diminish of sulfur vacancy. The regulation of sulfur vacancies by Ni doping and their interplay on photocatalytic CO2RR activity are presented and discussed. This work provides an in-depth insight of the role of dopant on vacancy modulation in photocatalyst beyond light absorption and a guidance for design of the potential photocatalyst for CO2RR.

    关键词: CO2 reduction,vacancy,photocatalysis,doping,ZnS

    更新于2025-11-19 16:51:07

  • Cell viability assessments of green synthesized water-soluble AgInS <sub/>2</sub> /ZnS core/shell quantum dots against different cancer cell lines

    摘要: Chalcopyrite quantum dots (QDs) have emerged as a safe alternative to cadmium-based QDs for bio-applications. However, the research on AgInS2 chalcopyrite QDs has not been widely explored in terms of their toxicity. Herein, we report a synthesis of biocompatible AgInS2/ZnS QDs via a greener approach. The emission intensity of the as-synthesized AgInS2 core QDs was enhanced 2-fold after the ZnS shell growth. X-ray diffraction revealed the tetragonal crystal structure of QDs, and high-resolution transmission electron microscope images show that the QDs are spherical in shape and crystalline in nature. Cell viability assays conducted on different cell lines, such as HeLa, A549, and BHK-21 cells, indicated that AgInS2/ZnS QDs are least toxic at a QD concentration range of 100 lg/mL. The ?uorescent microscope analysis of A549 cells incubated with AgInS2/ZnS QDs shows that the QDs were accumulated in the cell membranes. The as-synthesized AgInS2/ZnS QDs are less toxic and eco-friendly, and can be used for biolabeling.

    关键词: cell viability,AgInS2/ZnS,biolabeling,Chalcopyrite quantum dots,biocompatibility

    更新于2025-11-19 16:46:39

  • A novel fluorescent probe for H2O2 detection based on CdSe@ZnS quantum dots/Ag nanocluster hybrid

    摘要: The selective and quantitative detection of H2O2 is important for its employment in physiological, environmental and industrial applications. In this paper, a sensitive and selective strategy for H2O2 detection was established based on the fluorescence quenching of CdSe@ZnS quantum dots (QDs) by H2O2-mediated etching process of Ag nanoclusters (AgNCs). In this strategy, dihydrolipoic acid (DHLA) modified AgNCs were applied as H2O2 response group, the existence of H2O2 could initiate the oxidation of AgNCs and the production of Ag+, which could give rise to the effective fluorescence quenching of CdSe@ZnS QDs. Based on this strategy, the present fluorescent assay could realize the quantificational detection of H2O2 and the limit of detection is calculated to be 0.3 mM under the optimum conditions. Furthermore, CdSe@ZnS/AgNCs hybrid-based probe was applied to detecting H2O2 in milk samples and showed a good recoveries results ranged from 95.8% to 112.0%, meaning the potential applicability of this strategy.

    关键词: H2O2 detection,Ag nanoclusters,Fluorescence quenching,CdSe@ZnS quantum dots

    更新于2025-11-19 16:46:39

  • One-step Aqueous Synthesis of Zn-based Quantum Dots as Potential Generators of Reactive Oxygen Species

    摘要: The actual incorporation of dopant species into the ZnS Quantum Dots (QDs) host lattice will induce structural defects evidenced by a red shift in the corresponding exciton. The doping should create new intermediate energetic levels between the valence and conduction bands of the ZnS and affect the electron-hole recombination. These trap states would favour the energy transfer processes involved with the generation of cytotoxic radicals, so-called Reactive Oxygen Species, opening the possibility to apply these nanomaterials in cancer research. Any synthesis approach should consider the direct formation of the QDs in biocompatible medium. Accordingly, the present work addresses the microwave-assisted aqueous synthesis of pure and doped ZnS QDs. As-synthesized quantum dots were fully characterized on a structural, morphological and optical viewpoint. UV-Vis analyzes evidenced the excitonic peaks at approximately 310 nm, 314 nm and 315 nm for ZnS, Cu-ZnS and Mn-ZnS, respectively, Cu/Zn and Mn/Zn molar ratio was 0.05%. This indicates the actual incorporation of the dopant species into the host lattice. In addition, the Photoluminescence spectrum of non-doped ZnS nanoparticles showed a high emission peak that was red shifted when Mn2+ or Cu2+ were added during the synthesis process. The main emission peak of non-doped ZnS, Cu-doped ZnS and Mn-doped ZnS were observed at 438 nm, 487 nm and 521 nm, respectively. Forthcoming work will address the capacity of pure and Cu-, Mn-ZnS quantum dots to generate cytotoxic Reactive Oxygen Species for cancer treatment applications.

    关键词: Cancer research,ZnS Quantum Dots,Doping,Microwave-assisted synthesis,Reactive Oxygen Species

    更新于2025-11-19 16:46:39

  • Composition-gradient ZnO/Zn(S,O) heterostructure nanorod arrays and their cathodoluminescence

    摘要: Well-aligned ZnO/Zn(S,O) heterostructure nanorods have been synthesized through a well-designed chemical vapor deposition synthesis process. The as-synthesized ZnO/Zn(S,O) heterostructures exhibit a single crystal characteristic and a transitive interface with obvious composition gradient. X-ray Energy dispersive spectrometer (EDS) analysis demonstrates that ZnS-phase is rich in the nanorod bottom during the initial nucleation process and the S element content has a drastic decrease along the heterostructure nanorod from the bottom to the top, while O element is spatially detected in the whole rod. Room-temperature cathodoluminescence measurements verify two UV emissions at 330 nm and 385 nm for respective Zn(S,O) and ZnO phases with a strong defect-related emission band in visible range. Finally, the growth mechanism and optical emissions of ZnO/Zn(S,O) heterostructure nanorods are discussed.

    关键词: ZnS,Heterostructures,ZnO,Synthesis,Cathodoluminescence

    更新于2025-11-14 17:15:25

  • Defective ZnS nanoparticles anchored in situ on N-doped carbon as a superior oxygen reduction reaction catalyst

    摘要: Defect engineering has been used to develop low-cost and effective catalysts to boost oxygen reduction reactions. However, the development of catalysts that use metal cation vacancies as the active sites for oxygen reduction reaction is lacking. In this study, ZnS nanoparticles on N-doped carbon serve as an oxygen reduction reaction catalyst. These catalysts were prepared via a one-step method at 900 °C. Amazingly, the high-resolution transmission electron microscope image revealed obvious defects in the ZnS nanoparticles. These facilitated the catalyst synthesis, and the product displayed good electrocatalytic performance for the oxygen reduction reaction in an alkaline medium, including a lower onset potential, lower mid-wave potential, four electron transfer process, and better durability compared with 20 wt% Pt/C. More importantly, the density functional theory results indicated that using the Zn vacancies in the prepared catalyst as active sites required a lower reaction energy to produce OOH ? from ?OO toward oxygen reduction reaction. Therefore, the proposed catalyst with Zn vacancies can be used as a potential electrocatalyst and may be substitutes for Pt-based catalysts in fuel cells, given the novel catalyst’s resulting performance.

    关键词: Density functional theory calculations,Oxygen reduction reaction,Zn vacancy,Electrocatalyst,Defective ZnS nanoparticle

    更新于2025-11-14 17:03:37

  • Synthesis and characterization of S-doped-rGO/ZnS nanocomposite for the photocatalytic degradation of 2-chlorophenol and disinfection of real dairy wastewater

    摘要: In this study, a facile one-pot method has been used for the synthesis of zinc sulfide decorated sulfur-doped reduced graphene-oxide (S-rGO/ZnS) nanocomposite. The photocatalytic applications of ZnS and S-rGO/ZnS) nanocomposite is investigated for the decontamination and disinfection of 2-chlorophenol (2-CP) and real dairy wastewater. The physico-chemical characteristics of ZnS and S-rGO/ZnS were analyzed using photoluminescence spectroscopy, UV visible spectroscopy, scanning electron microscopy and x-ray diffraction. The experimental findings revealed that the S-rGO/ZnS nanocomposite own superior photocatalytic activity with 99.3 % degradation of 2-chlorophenol within four hours of solar light exposure. Furthermore, the antimicrobial potential of S-rGO/ZnS was also highlighted with the observed high disinfection potential while treatment of dairy wastewater. Overall, this study may offer useful insights to established visible light S-rGO/ZnS nanocomposite having the potential to be efficiently used for multiple applications in wastewater purification.

    关键词: 2-chlorophenol,photocatalysis,dairy wastewater,COD,antimicrobial activity,S-rGO/ZnS

    更新于2025-11-14 15:26:12

  • Effect of RF power on the structural and optical properties of ZnS thin films prepared by RF-sputtering

    摘要: Zinc sulphide (ZnS) thin films have grown on glass and Si substrates by reactive cathodic radio frequency (RF) sputtering. The RF power was varied in the range of 100 to 250 W, while the deposition time is set at 75 min. The optical, structural, and morphological properties of these thin films have been studied. The optical properties (mainly thickness, refractive index, absorption coefficient, and optical band gap) were investigated by optical transmittance measurements in the wavelength range of ultraviolet-visible-near infrared spectroscopy and spectroscopy infrared with Fourier transform. Fourier (FT-IR) and XRD analysis indicated that all sputtering ZnS films had a single-phase with a preferred orientation along the (111) plane of the zinc sphalerite phase (ZB). The crystallite size ranged from 11.5 to 48.5 nm with RF power getting a maximum of 200 W. UV–visible measurements exhibited that the ZnS film had more than 80% transmission in the visible wavelength region. In addition, it has been observed that the band gap energy of ZnS films is decreased slightly from 3.52 to 3.29 eV, and as the RF power is increased, the film thickness increases with the speed of deposit growth. Scanning electron microscopy observations revealed the types of smooth-surfaced films. The measurements (FT-IR) revealed at wave number 1118 and 465.02 cm?1 absorption bands corresponding to the symmetrical and asymmetric vibration of the Zn–S stretching mode. X-ray reflectometry measurements of ZnS films have shown that the density of the films is (3.9 g/cm3) close to that of solid ZnS.

    关键词: RF-sputtering ZnS,ZnS buffer layer for solar cell,ZnS thin films by sputtered

    更新于2025-09-23 15:23:52