- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Multifunctional Ag@NaGdF4:Yb3+, Er3+ core-shell nanocomposites for dual-mode imaging and photothermal therapy
摘要： Multifunctional core-shell nanostructure, which can be applied on bio-imaging and photothermal therapy (PTT), has attracted tremendous interest in recent years. Here, Ag@NaGdF4:Yb3+, Er3+ core-shell nanostructure incorporating luminescent, magnetic and photothermal conversion properties was prepared via a simple method. The as-prepared nanocomposites (NCs) exhibit uniform core-shell sphere morphology, green up-conversion luminescence (UCL), good paramagnetic and photothermal conversion behaviors. The luminescence resonance energy transfer (LRET) between Ag nanoparticles (NPs) and NaGdF4:Yb3+, Er3+ NPs were researched. The cytotoxicity test on HeLa cells using methyl thiazolyltetrazolium (MTT) assay shows good biocompatibility of the core-shell NCs. Moreover, in vitro computed tomography (CT) and UCL imaging studies and in vitro PTT of living assay suggest that the core-shell NCs can be used as theranostic nanoagents for dual-mode imaging guided PTT for tumor.
关键词： Dual-mode imaging,Core-shell structure,Multifunctional nanocomposites,Photothermal therapy
更新于2025-09-19 17:15:36
-
Binding energy of an exciton in a GaN/AlN nanodot: Role of size and external electric field
摘要： We report the impact of an external electric field on the energy spectrum of an exciton inside a spherical shaped GaN/AlN core/shell nanodot. The modulation of the confined exciton lowest state energy by the nanodot size is also treated. Our theoretical approach, based on a variational calculation, predicts a remarkable decrease in the exciton's energy when the electric field is switched on. Furthermore, our investigation shows that for a fixed nanodot size, the energy redshift is a unique function of the external electric field strength. On the other hand, it was observed that as the nanodot size increases the lowest exciton energy decreases and vice versa.
关键词： electric field,core/shell materials,nanostructures,quantum dots,exciton
更新于2025-09-19 17:15:36
-
Enhanced gas-sensing performance of metal@ZnO core–shell nanoparticles towards ppb–ppm level benzene: the role of metal–ZnO hetero-interfaces
摘要： Core–shell metal@ZnO nanoparticles including Au@ZnO, Pd@ZnO and Pt@ZnO were synthesized and utilized for sensing low-concentration benzene. Various techniques were used to characterize the compositional properties of the typical core@shell structure and analyze the relation between the sensing properties and the metal–ZnO hetero-interfaces. When applied as gas-sensing materials, all three core–shell metal@ZnO nanoparticles showed better sensing performance than pure ZnO nanoparticles towards low concentration benzene. In particular, the gas-sensing response of the Pt@ZnO core–shell nanoparticles was 7 times higher than that of pure ZnO towards 0.1 ppm benzene and 63 times higher towards 5 ppm benzene, which was more sensitive than most gas-sensing materials in previous literature. Furthermore, the Pt@ZnO core–shell nanoparticles presented an ultra-low detection limit of no less than 10 ppb, which was lower than those of most gas-sensing materials in previous literature. Besides, the Pt@ZnO core–shell nanoparticles showed high selectivity and long-term response stability with a response value of 2.7 ± 1.6% towards 1 ppm benzene after operating for a month. The enhanced gas-sensing performances of the metal@ZnO core–shell nanoparticles are well correlated to the work function differences between the contacted metal and ZnO within the metal–ZnO hetero-interfaces, which produce high Schottky energy barriers and modulate the electron transfer.
关键词： gas-sensing,Schottky barrier,core–shell nanoparticles,benzene,metal–ZnO hetero-interfaces
更新于2025-09-19 17:15:36
-
Core–shell structured poly(vinylidene fluoride)- <i>grafted</i> -BaTiO <sub/>3</sub> nanocomposites prepared <i>via</i> reversible addition–fragmentation chain transfer (RAFT) polymerization of VDF for high energy storage capacitors
摘要： Core–shell structured poly(vinylidene fluoride)-grafted-barium titanate (PVDF-g-BaTiO3) nanocomposites were prepared by surface-initiated reversible addition–fragmentation chain transfer (RAFT) polymerization of VDF from the surface of functionalized BaTiO3 nanoparticles. The ceramic fillers were first surface-modified with xanthate functions to further allow the RAFT grafting of VDF. A series of structured core shells were synthesized by tuning the feed [initiator functionalized nanoparticles]0 : [monomer]0 ratio, varying from 3 to 5, 10 and 20 wt%. Fourier transform infrared spectroscopy (FTIR), high resolution magic angle spinning (HRMAS) NMR and thermogravimetric analysis (TGA) confirmed the successful surface functionalization of the ceramic filler and the grafting of the PVDF shell onto the surface of the BaTiO3 cores. Transmission electron microscopy results revealed that BaTiO3 nanoparticles are covered by thin shells of PVDF, with thickness varying from 2.2 to 5.1 nm, forming a core–shell structure. HRMAS 19F indicated a grafting of 39–50 units of VDF. X-ray diffraction measurements together with FTIR measurements revealed that PVDF was present in the α form. Thermal properties also indicated that the addition of a small amount of the BaTiO3 filler to the PVDF matrix increased the melting temperature from 168 °C for neat PVDF to 173 °C for PVDF-g-BaTiO3 (20 wt%) and decreased the crystallinity of PVDF from 47% to 21%.
关键词： Nanocomposites,Core-Shell Structure,BaTiO3,PVDF,RAFT Polymerization,Polymer Chemistry,Dielectric Materials
更新于2025-09-19 17:15:36
-
N-Doped K3Ti5NbO14@TiO2 Core-Shell Structure for Enhanced Visible-Light-Driven Photocatalytic Activity in Environmental Remediation
摘要： A novel N-doped K3Ti5NbO14@TiO2 (NTNT) core-shell heterojunction photocatalyst was synthesized by firstly mixing titanium isopropoxide and K3Ti5NbO14 nanobelt, and then calcinating at 500 °C in air using urea as the nitrogen source. The samples were analyzed by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis absorption spectroscopy and X-ray photoelectron spectroscopic (XPS) spectra. Anatase TiO2 nanoparticles were closely deposited on the surface of K3Ti5NbO14 nanobelt to form a nanoscale heterojunction structure favorable for the separation of photogenerated charge carriers. Meanwhile, the nitrogen atoms were mainly doped in the crystal lattices of TiO2, resulting in the increased light harvesting ability to visible light region. The photocatalytic performance was evaluated by the degradation of methylene blue (MB) under visible light irradiation. The enhanced photocatalytic activity of NTNT was ascribed to the combined effects of morphology engineering, N doping and the formation of heterojunction. A possible photocatalytic mechanism was proposed based on the experimental results.
关键词： visible-light photodegradation,core-shell structure,TiO2,K3Ti5NbO14 nanobelt
更新于2025-09-19 17:15:36
-
<i>In situ</i> synthesis of n–n Bi <sub/>2</sub> MoO <sub/>6</sub> & Bi <sub/>2</sub> S <sub/>3</sub> heterojunctions for highly efficient photocatalytic removal of Cr( <scp>vi</scp> )
摘要： Exploiting novel photocatalysts with high efficiency and durability for reduction of hexavalent chromium (Cr(VI)) has gained attention from fundamental science and industrial research. In this work, we synthesized novel two-dimensional (2D) n–n Bi2MoO6 & Bi2S3 heterojunctions by a facile in situ anion exchange process for remarkably efficient removal of Cr(VI). Results show that Bi2MoO6 & Bi2S3 heterojunctions with core–shell structures are formed through the intimate contact of Bi2MoO6 core and Bi2S3 shell. The prepared Bi2MoO6 & Bi2S3 heterojunctions exhibit unprecedented photocatalytic activity for reduction of Cr(VI) under visible light irradiation. The optimized BMO-S1 heterojunction displays the highest reduction efficiency (kapp = 0.164 min?1) for Cr(VI) reduction. To the best of our knowledge, it is one of the highest reduction rate achieved among reported photocatalysts for Cr(VI) reduction under visible-light irradiation. Detailed studies show that strong selective adsorption for Cr(VI) enhances this unprecedented photocatalytic activity. Moreover, the intimate heterojunction between Bi2MoO6 core and Bi2S3 shell can efficiently deteriorate the charge carrier recombination and Bi2S3 content can boost visible light harvesting, thereby contributing to the remarkable photocatalytic catalytic activity, which were proven by PL, EIS and transient photocurrent responses. Characterization of Mott–Schottky plots and DRS prove that the Bi2MoO6 & Bi2S3 heterojunctions established a type-II band alignment with intimate contact, accounting for the efficient transfer and separation of photogenerated carriers. This work provides a simple route for facial synthesis of heterojunction photocatalysts for Cr(VI) reduction in industrial applications.
关键词： photocatalytic,visible light,Cr(VI) reduction,heterojunctions,Bi2S3,core-shell structure,Bi2MoO6
更新于2025-09-19 17:15:36
-
CdTe@SiO2 signal reporters-based fluorescent immunosensor for quantitative detection of prostate specific antigen
摘要： In this paper, an immunosensor using CdTe@SiO2 core-shell nanoparticles as labels was constructed for highly sensitive detection of prostate-specific antigen (PSA). In this approach, CdTe@SiO2 core-shell nanoparticles were synthesized using the sol-gel method. The additional Cd ions and sulfur source in SiO2 shell can greatly enhance the fluorescence intensity of CdTe nanocrystals. The reason is the formation of CdS-like cluster in SiO2 shell, which reduced the quantum size effect. The obtained CdTe@SiO2 nanoparticles also exhibited excellent biocompatibility, which was ideal for applying in biomarker detection. Furthermore, PSA capture antibodies functionalized magnetic Fe3O4 nanoparticles (Fe3O4-Ab1) were utilized in the proposed immunosensor to capture and enrich the PSA. The captured PSA was then immuno-recognized by CdTe@SiO2 labeled with PSA detection antibodies (CdTe@SiO2-Ab2) by forming the sandwich complex Fe3O4-Ab1/PSA/Ab2-CdTe@SiO2. The construction of this immunosensor was confirmed by fluorescence spectroscopy. The proposed immunosensor showed a good linear relationship between the fluorescent intensity and the target PSA concentration ranging from 0.01 to 5 ng/mL, and a detection limit as low as 0.003 ng/mL was achieved. The sensor also exhibited good specificity to PSA. This highly sensitive and specific immunosensor has great potential to be used in other biological detection.
关键词： Quantum Dots,Core-shell,Prostate Specific Antigen,Immunosensor
更新于2025-09-19 17:15:36
-
Efficient electrochemical detection and extraction of copper ions using ZnSe-CdSe/SiO2 core-shell nanomaterial
摘要： Development of nanostructured materials has received tremendous attention nowadays due to their unique properties and efficacious in wide range of applications. Herein, we present a facile synthesis of ZnSe-CdSe/SiO2 core-shell nanomaterial for pollutants monitoring and environmental remediation purposes. The utility of ZnSe-CdSe/SiO2 core-shell nanomaterial was explored toward electrochemical detection and adsorptive removal of copper ions from aquatic system. Experimental results reveal that both electrochemical detection and adsorption of Cu(II) using ZnSe-CdSe/SiO2 nanomaterial strongly depends on the solution pH, with an optimum pH of 5. Based on the results, the amperometric sensor based on ZnSe-CdSe/SiO2 core-shell nanomaterial modified electrode exhibited a detection limit of 50 μgL?1. Moreover, ZnSe-CdSe/SiO2 core-shell nanomaterial as adsorbent demonstrated high uptake capacity equals to 126.25 mgg?1. Thus, ZnSe-CdSe/SiO2 core-shell nanomaterial can be employed as promising material for several environmental remediation purposes.
关键词： Core-shell,Adsorption,Copper,ZnSe-CdSe/SiO2,Electrochemical Sensor,Nanomaterial,Extraction
更新于2025-09-19 17:15:36
-
Core-shell structure-induced high displacement response in piezoelectric ceramics: A theoretical design
摘要： In this work, a series of piezoelectric composites with core-shell structure are proposed to pursue high displacement response under a low applied electric field. The shell and core consist of piezoelectric and non-piezoelectric material, respectively. A finite element method (FEM) is introduced to simulate the distribution of local electric field and the displacement response. The results show that the largest piezoelectric displacement response of these core-shell structural composites reaches twenty-five times larger than that of pure piezoelectric ceramic under the applied electric field of 2 kV/mm, which can be explained by the fact that the local electric field inside the shell is enhanced up to dozens of times as large as the applied electric field. It is also suggested that the displacement response of piezoelectric composites can be heightened by adopting smaller shell volume fraction, or increasing the permittivity or decreasing the Young's modulus of the core.
关键词： Displacement response,Finite element method (FEM),Core-shell structure,Piezoelectric
更新于2025-09-19 17:15:36
-
Green-amber emission from high indium content InGaN quantum wells improved by interface modification of semipolar (112?2) GaN templates
摘要： The Na-ion hybrid capacitor (NIC) has exhibited its potential applications for devices that need high energy and power densities with low cost. Nevertheless, due to their 'Daniell-type' mechanism, conventional NIC devices require massive electrolytes to provide a good ionic conductivity during charging, which could decrease the packaged energy density. Herein, we report a novel 'Rocking-Chair' Na-ion hybrid capacitor (RC-NIC) employing Na-ions as charge carriers, Na3V2O2(PO4)2F@PEDOT as the cathode material and activated carbon (AC) as the anode material. RC-NIC efficiently improves the energy density by minimizing the amount of electrolyte like secondary batteries because Na-ion is de-intercalated from the cathode while it is adsorbed to the anode during charging. The Na3V2O2(PO4)2F@PEDOT//AC (peanut shell derived carbon) RC-NIC delivers high energy density of 158 W h kg?1 and power density of 7000 W kg?1 based on the total mass of active materials in both electrodes, respectively, in the voltage window of 1.0–4.2 V. This is one of the highest energy densities among the previously reported NICs. This concept provides a new route to build sodium-ion hybrid capacitors that meet dual criteria of battery and supercapacitor characters.
关键词： Na-ion hybrid capacitor,core–shell nanorods,energy storage,Na3V2O2(PO4)2F@PEDOT,rocking-chair mechanism
更新于2025-09-19 17:15:36