- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
EXPRESS: A Study of the Surface of Fe <sub/>3</sub> O <sub/>4</sub> @SiO <sub/>2</sub> Nanoparticles Functionalized with Different Groups Using a Photoacoustic Infrared Spectroscopic Method
摘要： A permanent development of hybrid materials based on the highly absorptive or opaque materials has prompted a need of analytical tools, which are able to overcome obstacles connected with their physicochemical features. Iron oxide (II, III) (Fe3O4) nanoparticles gained a huge attention as supporters, as they are not only easily accessible using various synthetic approaches, but they also exhibit homogeneity and paramagnetic properties, which make them easily separable materials. Nevertheless, the classic infrared spectroscopic studies might meet several problems with characterization of such systems. Therefore, infrared spectroscopy in photoacoustic mode using Fourier transform infrared–photoacoustic infrared spectroscopy (FT-IR PAS) can be an extremely sensitive and exact analytical tool for investigation of the magnetite-based hybrid materials surface. Herein, we present a synthesis of Fe3O4 nanoparticles using co-precipitation method with their subsequent encapsulation within silica matrix decorated with different silanes containing various terminal functional groups. The proper syntheses of core/shell structures were confirmed using the FT-IR PAS method. Each spectrum exhibited specific bands corresponding to vibrations of magnetite particles, silica lattice and particular surface functional groups, which strictly indicated successful grafting of silanes onto Fe3O4 surface.
关键词： PAS,Magnetite nanoparticles,Fourier transform infrared,core/shell structures,surface analysis,photoacoustic infrared spectroscopy,FT-IR PAS,FT-IR
更新于2025-09-19 17:13:59
-
Plasmon-coupled Charge Transfer in FSZA Core-shell Microspheres with High SERS Activity and Pesticide Detection
摘要： A commercial SeRS substrate does not only require strong enhancement, but also can be reused and recycled in actual application. Herein, fe3o4/Sio2/Zno/Ag (fSZA) have been synthesised, which consisted of fe3o4 core with strong magnetic field response and an intermediate SiO2 layer as an electronic barrier to keep the stability of magnetite particles and outer ZnO and Ag as the effective layers for detecting pollutants. The SERS enhancement factor (EF) of the FSZA was ~8.2 × 105. the enhancement mechanism of the fSZA core-shell microspheres were anatomized. the electromagnetic enhancement of surface deposited Ag, charge transfer, and molecular and exciton resonances act together to cause such high enhancement factors. for practical application, the fSZA core-shell microspheres were also used to detect thiram, moreover, which was collected and separated by an external magnetic field, and maintained the SERS activity without significant decline during multiple tests. So the good enhancement performance and magnetic recyclability make the fSZA core-shell microspheres a promising candidates for practical SeRS detection applications.
关键词： pesticide Detection,plasmon-coupled charge transfer,High SeRS Activity,fSZA core-shell Microspheres
更新于2025-09-19 17:13:59
-
Macroscopic Au@PANI Core/shell Nanoparticle Superlattice Monolayer Film with Dual-responsive Plasmonic Switches
摘要： The self-assembled gold nanoparticles superlattice displays unusual but distinctive features such as highly mechanical and free-standing performance, electrical conductivity and plasmonic properties, which were widely employed in various applications especially in biological diagnostics and optoelectronic devices. Two-dimensional (2D) superlattice monolayer film composed of a given metal nanostructure, it is rather challenging to tune either its plasmonic properties or its optical properties in a reversible way, and it is not reported. It is therefore of significant value to construct free-standing 2D superlattice monolayer film of gold nanoparticles with intelligent response and desired functions. Herein, we developed an easy and efficient approach to construct gold nanoparticles superlattice film with a dual-responsive plasmonic switch. In this system, gold nanoparticles were firstly coated by polyaniline (PANI), and then interracially self-assembled into monolayer film at the air-liquid interface. PANI shell plays two important roles in superlattice monolayer film. Firstly, PANI shell acts as a physical spacer to provide a steric hindrance to counteract the van der Waals (vdWs) attraction between densely packed nanoparticles (NPs), resulting in the formation of superlattice by adjusting the thickness of the PANI shell. Secondly, PANI shells provide superlattice film with multiple stimuli such as electrical potential and pH change, leading to reversible optical and plasmonic responsive. Superlattice monolayer film can show a vivid color change from olive green to pink, or from olive green to violet by the change of corresponding stimuli. And the localized surface plasmonic resonance (LSPR) of superlattice monolayer film can be reversibly modulated by changing both local pH and applying electric potential. Notably, a significant plasmonic shift of superlattice monolayer film can be achieved to 157 nm, when PANI shell with the thickness of 35 nm and gold nanorods as core were used. The superlattice monolayer film with dual-responsive plasmonic switches is promising for a range of potential applications in optoelectronic devices, plasmonic and colorimetric sensors, and Surface enhanced Raman scattering (SERS).
关键词： plasmonic switching,dual-responsive,superlattice,2D monolayer film,core shell structure
更新于2025-09-19 17:13:59
-
Zirconium Nitride for Plasmonic Cloaking of Visible Nanowire Photodetectors
摘要： Light scattered by a photodetector disturbs the probing field, resulting in noise. Cloaking is an effective method to reduce this noise. Here we investigate theoretically an emerging plasmonic material, zirconium nitride (ZrN), as a plasmonic cloak for silicon (Si) nanowire-based photodetectors and compare it with a traditional plasmonic material, gold (Au). Using Mie formalism, we have obtained the scattering cancelation across the visible spectrum. We found that ZrN cloaks produce a significant decrease in the scattering from bare Si nanowires, which is 40% greater than that obtained with Au cloaks in the wavelength region of 400–500 nm. The scattering cancelations become comparable at 550 nm, with Au providing a better scattering cancelation compared to ZrN over the wavelength region of 600–700 nm. To include the absorption and provide a measure of overall performance on noise reduction, a figure of merit (FOM), defined as the ratio of the absorption efficiency and the scattering efficiency of the cloaked nanowire to that of the bare Si nanowire, was calculated. We show that the optimized ZrN cloak provides up to 3 times enhancement of the FOM over a bare Si NW and a 60% improvement over an optimized Au-cloaked NW, in the wavelength region of 400–500 nm. An optimized Au-cloaked NW shows up to 17.69 times improvement in the wavelength region of 600–700 nm over a bare Si NW and up to a 2.7 times improvement over an optimized ZrN-cloaked NW. We also predicted the optimal dimensions for the cloaked NWs with respect to the largest FOM at various wavelengths between 400 and 650 nm.
关键词： Plasmonic cloaking,Core-shell,Nanowires,Emerging plasmonic materials,Zirconium nitride,Scattering cancelation
更新于2025-09-19 17:13:59
-
Nonvolatile Resistive Switching Memory Device Employing CdSe/CdS Core/Shell Quantum Dots as an Electrode Modification Layer
摘要： Accompanied with great advantages in various fields of performance, memristors show huge potential in the next generation of mainstream storage devices. However, their random distribution of resistance switching voltage has always been one of the problems in applications. In this present work, a nonvolatile resistive switching memory device was proposed, which employed CdSe/CdS core/shell quantum dots (QDs) assembled as an electrode modification layer with the device configuration of Pt/CdSe-CdS QDs/TaOx/Ta. The device possesses multiple excellent resistance switching characteristics such as lower and more consistent set/reset threshold voltage and better endurance performance, which is considered as the effect of the electrode modification layer based CdSe/CdS core/shell QDs. A model with uneven QDs/Pt electrode interface was put forward to explain the different resistance switching behaviors, which may be beneficial to the development of existing research about memristors based on metal oxides and quantum dots.
关键词： Migration,Oxygen vacancy,Schottky interface,CdSe/CdS core/shell quantum dots,resistive switching
更新于2025-09-19 17:13:59
-
Core-Shell ZnO@SnO2 Nanoparticles for Efficient Inorganic Perovskite Solar Cells
摘要： The ideal charge transport materials should exhibit a proper energy level, high carrier mobility, sufficient conductivity, and excellent charge extraction ability. Here, a novel electron transport material was designed and synthesized via using a simple and facile solvothermal method, which is composed by the core-shell ZnO@SnO2 nanoparticles. Thanks to the good match between energy level of SnO2 shell and high electron mobility of core ZnO nanoparticles, the PCE of inorganic perovskite solar cells has reached 14.35% (JSC: 16.45 mA cm-2, VOC: 1.11 V, FF: 79%), acting core-shell ZnO@SnO2 nanoparticles as the electron transfer layer. The core-shell ZnO@SnO2 nanoparticles size is 8.1 nm with the SnO2 shell thickness of 3.4 nm, and the electron mobility is seven times more than SnO2 nanoparticles. Meanwhile, the uniform core-shell ZnO@SnO2 nanoparticles is extremely favorable to the growth of inorganic perovskite films. These preliminary results strongly suggest the great potential of this novel electron transfer material in high-efficiency perovskite solar cells.
关键词： inorganic perovskite solar cells,electron transport material,solvothermal method,core-shell ZnO@SnO2 nanoparticles,high electron mobility
更新于2025-09-19 17:13:59
-
Core/Shell Quantum Dots Solar Cells
摘要： Semiconductor nanocrystals, the so-called quantum dots (QDs), exhibit versatile optical and electrical properties. However, QDs possess high density of surface defects/traps due to the high surface-to-volume ratio, which act as nonradiative carrier recombination centers within the QDs, thereby deteriorating the overall solar cell performance. The surface passivation of QDs through the growth of an outer shell of different materials/compositions called “core/shell QDs” has proven to be an effective approach to reduce the surface defects and confinement potential, which can enable the broadening of the absorption spectrum, accelerate the carrier transfer, and reduce exciton recombination loss. Here, the recent research developments in the tailoring of the structure of core/shell QDs to tune exciton dynamics so as to improve solar cell performance are summarized. The role of band alignment of core and shell materials, core size, shell thickness/compositions, and interface engineering of core/thick shell called “giant” QDs on electron–hole spatial separation, carrier transport, and confinement potential, before and after grafting on the carrier scavengers (semiconductor/electrolyte), is described. Then, the solar cell performance based on core/shell QDs is introduced. Finally, an outlook for the rational design of core/shell QDs is provided, which can further promote the development of high-efficiency and stable QD sensitized solar cells.
关键词： core/shell quantum dots,carrier dynamics,solar cells,interface engineering
更新于2025-09-19 17:13:59
-
Self‐assembled core‐shell structured organic nanofibers fabricated by single‐nozzle electrospinning for highly sensitive ammonia sensors
摘要： Electrospinning is a unique method to prepare 1-dimentional nanofiber for large-scale manufacturing. Here in, we demonstrated chemical sensors based on the semiconducting nanofibers with core-shell structure by simple single-nozzle electrospinning with the spontaneous phase separation. The core-shell structure nanofiber has large active sites which make it highly sensitive to chemical analytes. The thickness of the sensing shell can be tuned by controlling the mass ratio of core and shell components. As a demonstration, the nanofiber-based sensor exhibits high sensitivity to low-concentration ammonia (ppb level), as well as stability and reversibility. This unique fast single-nozzle electrospinning technique used to fabricate semiconducting nanofibers with core-shell structure provides a facile and designable process for the integration of multifunctional organic semiconducting layer into the organic electronic system.
关键词： nanofiber,chemical sensor,core-shell structure,electrospinning
更新于2025-09-19 17:13:59
-
Enrichment and Identification of Metallothionein by Functionalized Nano-Magnetic Particles and Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry
摘要： As a low molecular weight protein with the ability of binding metal ions and high inducibility, metallothionein (MT) is often regarded as an important biomarker for assessment of heavy metal pollution in water environment. In the light of that the traditional process of enrichment and identification is time-consuming and complicated, we prepared a core-shell nanoparticle, gold-coated iron oxide nanoparticles (Fe3O4@Au NPs) herein. It possessed the advantages of fast response to magnetic fields and optical properties attributing to Fe3O4 and Au nanoparticles, respectively. The Fe3O4@Au nanoparticles could be used to enrich MT simply through Au–S interaction, and the purified proteins were determined by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS). The results showed that the Fe3O4@Au nanoparticles could directly enrich MT from complex solutions and the detection limit could be as low as 10 fg mL?1.
关键词： Core-shell structure,Mass spectrometry,Low-abundant,Metallothionein,Gold nanoparticles,Magnetic nanomaterials
更新于2025-09-19 17:13:59
-
Plasmonic mesoporous core-shell Ag-Au@TiO2 photoanodes for efficient light harvesting in dye sensitized solar cells
摘要： In this study, plasmonic mesoporous core-shell Ag-Au@TiO2 nanocomposites were synthesized by seed-mediated growth of Ag shell onto Au decorated TiO2 and utilized as photoanodes to enhance the power conversion efficiency (PCE) of dye-sensitized solar cells. The enhanced preserved mesoporous characteristics of photoanodes, together with strong metal-dielectric interfacial interaction between Ag-Au shell, remarkably improved electron transfer ability onto TiO2, which caused to the enhancement of the light harvesting (η = 7.41% using Ag-Au@TiO2) 125% higher than bare TiO2 (η = 5.91%). These superior PCE value was mainly due to the shifting of the Fermi level close to the TiO2 conduction band thanks to the broad band localized surface plasmon resonance (LSPR) properties between Ag-Au and TiO2 interfaces. The significant outperforming in enhanced solar to electrical energy conversion efficiency using low amount of Ag-Au@TiO2 photoanode (0.0125 wt%) demonstrated a relative low-cost solar device from the economic perspective of renewable energy fabrication resources.
关键词： Metal core-shell nanoparticles,Mesoporous structures,Plasmonic TiO2,Dye-sensitized solar cells,Localized surface plasmon resonance
更新于2025-09-19 17:13:59