scholarly journals Dynamic Hydrogen Production from Methanol/Water Photo-Splitting Using Core@Shell-Structured CuS@TiO2Catalyst Wrapped by High Concentrated TiO2Particles

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Younghwan Im ◽  
Sora Kang ◽  
Kang Min Kim ◽  
Taeil Ju ◽  
Gi Bo Han ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Reduction Potential ◽  
Hydrogen Gas ◽  
Electronic Transitions ◽  
Core Shell ◽  
High Concentration ◽  
Visible Absorption ◽  
Long Wavelength ◽  
The Core ◽  
Uv Visible

This study focused on the dynamic hydrogen production ability of a core@shell-structured CuS@TiO2photocatalyst coated with a high concentration of TiO2particles. The rectangular-shaped CuS particles, 100 nm in length and 60 nm in width, were surrounded by a high concentration of anatase TiO2particles (>4~5 mol). The synthesized core@shell-structured CuS@TiO2particles absorbed a long wavelength (a short band gap) above 700 nm compared to that pure TiO2, which at approximately 300 nm, leading to easier electronic transitions, even at low energy. Hydrogen evolution from methanol/water photo-splitting over the core@shell-structured CuS@TiO2photocatalyst increased approximately 10-fold compared to that over pure CuS. In particular, 1.9 mmol of hydrogen gas was produced after 10 hours when 0.5 g of 1CuS@4TiO2was used at pH = 7. This level of production was increased to more than 4-fold at higher pH. Cyclic voltammetry and UV-visible absorption spectroscopy confirmed that the CuS in CuS@TiO2strongly withdraws the excited electrons from the valence band in TiO2because of the higher reduction potential than TiO2, resulting in a slower recombination rate between the electrons and holes and higher photoactivity.

Study on the Inclusion Behavior of Cucurbit [n] uril with Phenylalanine

2011 ◽  
Vol 197-198 ◽  
pp. 1153-1156
Author(s):  
Ning Chen ◽  
Ya Bin Li
Keyword(s):  
1H Nmr ◽  
Interaction Mechanism ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
High Concentration ◽  
Buffer Solution ◽  
Visible Absorption ◽  
Nmr Spectrum ◽  
Application Range ◽  
Uv Visible

The characteristics of host-guest complexes between cucurbit[n]uril (CB [n]) and phenylalanine were investigated by UV-visible absorption spectroscopy in acetate buffer solution at room temperature. It was found that the UV-visible absorption increased steadily with constantly dropping the high concentration of cucurbit[6]uril (CB [6]) and cucurbit[8]uril (CB [8]) in the phenylalanine solution which indicates that there are some interaction betweenCB [n] and phenylalanine.Then CB [6] and phenylalanine at molar ratio of 1:1 to weigh while CB [8] and phenylalanine at molar ratio of 1:2, respectively, are both demonstrated by 1H NMR spectra. 1H NMR spectrum of complexes was obtained, indicating an enthalpic driving force for host-guest complexes. The possible interaction mechanism and inclusion mode were also discussed. This work may extend the application range of CB [n] in supramolecular and pharmaceutical analysis.

scholarly journals Magnetoliposomes Based on Magnetic/Plasmonic Nanoparticles Loaded with Tricyclic Lactones for Combined Cancer Therapy

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1905
Author(s):  
Irina S. R. Rio ◽  
Ana Rita O. Rodrigues ◽  
Juliana M. Rodrigues ◽  
Maria-João R. P. Queiroz ◽  
R. C. Calhelha ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Tumor Cells ◽  
Human Tumor ◽  
Plasmonic Nanoparticles ◽  
Core Shell ◽  
Triggered Release ◽  
Shell Nanoparticles ◽  
Visible Absorption ◽  
The Core ◽  
Average Size

Liposome-like nanoarchitectures containing manganese ferrite nanoparticles covered or decorated with gold were developed for application in dual cancer therapy, combining chemotherapy and photothermia. The magnetic/plasmonic nanoparticles were characterized using XRD, UV/Visible absorption, HR-TEM, and SQUID, exhibiting superparamagnetic behavior at room temperature. The average size of the gold-decorated nanoparticles was 26.7 nm for MnFe2O4 with 5–7 nm gold nanospheres. The average size of the core/shell nanoparticles was 28.8 nm for the magnetic core and around 4 nm for the gold shell. Two new potential antitumor fluorescent drugs, tricyclic lactones derivatives of thienopyridine, were loaded in these nanosystems with very high encapsulation efficiencies (higher than 98%). Assays in human tumor cell lines demonstrate that the nanocarriers do not release the antitumor compounds in the absence of irradiation. Moreover, the nanosystems do not cause any effect on the growth of primary (non-tumor) cells (with or without irradiation). The drug-loaded systems containing the core/shell magnetic/plasmonic nanoparticles efficiently inhibit the growth of tumor cells when irradiated with red light, making them suitable for a triggered release promoted by irradiation.

scholarly journals Nickel platinum (NixPt1−x) nanoalloy monodisperse particles without the core–shell structure by colloidal synthesis

2020 ◽  
Vol 2 (9) ◽  
pp. 3882-3889
Author(s):  
Cora Moreira Da Silva ◽  
Armelle Girard ◽  
Maxime Dufond ◽  
Frédéric Fossard ◽  
Amandine Andrieux-Ledier ◽  
...  
Keyword(s):  
Reduction Potential ◽  
Synthesis Temperature ◽  
Colloidal Synthesis ◽  
Core Shell ◽  
Monodisperse Particles ◽  
The Core ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Core Shell Structure ◽  
Nickel Platinum

Versatile colloidal route towards the synthesis of nanoalloys with controlled size and chemical composition, based on the correlation between the oxidation–reduction potential of metal cations in the precursors and the synthesis temperature.

Synthesis and Properties of TiO2/ZnO Core/Shell Nanomaterials

2007 ◽  
Vol 119 ◽  
pp. 239-242 ◽  
Author(s):  
Xiao Li Zhang ◽  
Young Hwan Kim ◽  
Young Soo Kang
Keyword(s):  
Thin Layers ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Peaks ◽  
Uv Visible ◽  
Zno Powder ◽  
Tio2 Phase

Core/shell structured TiO2/ZnO was synthesized in a basic aqueous solution through a simple hydrolyzing method. The powder X-ray diffraction (XRD) and transmission electron microscopy of the initial TiO2/ZnO powder showed diffraction peaks corresponding to the ZnO and TiO2 phase. The structure and thickness of ZnO shell (about 2.5 nm) coated TiO2 surface as thin layers or nanoclusters, depends upon the reactant concentration and the reaction time. The characteristics of the optical absorption were described by UV-visible absorption spectroscopy.

scholarly journals Conductivity Research on ABS & PC Converted Core Shell Quantum Dot Doped in ABS & PC

2019 ◽  
Vol 8 (4) ◽  
pp. 7740-7742
Keyword(s):  
Quantum Dot ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Wet Chemical ◽  
Uv Visible ◽  
Lcr Meter ◽  
Absorption Characteristics

Zns: Mn / ZnO inverted shell quantum dots have been synthesized using a wet chemical process.The study used Mn of 4 percent weight. Transmission Electron Microscope (TEM) images show a 50 nm order for the quantum dot size. Confirmation of the ZnO capped ZnSMn was done by TEM and X ray diffraction (XRD).The test band distance is measured using the UV Visible absorption characteristics. Measurement of the dielectric constant is done using the LCR meter

Preparation of SrS:Ce/ZnO Core-Shell Nanoparticles Using Reverse Micelle Method

2004 ◽  
Vol 829 ◽  
Author(s):  
Yusuke Kusakari ◽  
Shinji Ishizaki ◽  
Masakazu Kobayashi
Keyword(s):  
Reverse Micelle ◽  
Core Shell ◽  
Zno Nanoparticle ◽  
Shell Nanoparticles ◽  
Visible Absorption ◽  
Peak Intensity ◽  
Transmission Electron ◽  
Uv Visible ◽  
Core Shell Nanoparticles ◽  
Bright Blue

ABSTRACTSrS:Ce nanoparticles were prepared using a reverse micelle method and coated by ZnO. The mono-dispersed nanoparticles whose size was as small as 3nm were observed by transmission electron microscope (TEM) and dynamic light scattering (DLS) method. Optical properties of the core-shell SrS:Ce/ZnO nanoparticle was studied. UV-visible absorption and photoluminescence (PL) properties were measured and compared with those of SrS:Ce and SrS nanoparticles. Bright blue photoluminescence (around 440 nm) was observed from SrS:Ce at a room temperature when nanoparticles were excited using a Hg lamp. The PL peak intensity enhancement was observed after forming the ZnO shell. The optical absorption profile of nanoparticles was associated with the band edge feature of SrS. The coating of the SrS:Ce surface by ZnO has affected the electronic structure of SrS:Ce nanoparticles.

Synthesis and Characterization of SiO2/ZnO Core-Shell Spheres

2011 ◽  
Vol 320 ◽  
pp. 140-145
Author(s):  
Yung Kuan Tseng ◽  
Pei Han Wang ◽  
Shun Lung Su
Keyword(s):  
Uv Light ◽  
Spherical Surface ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Core Shell ◽  
Visible Absorption ◽  
Stöber Method ◽  
Eds Analysis ◽  
Uv Visible

This Study applies to Stöber method for synthesis an characterization of even-sized SiO2micrometer sphere; and then applies to sol-gel method for encapsulation for one layer of ZnO at SiO2spherical surface after regarded it as core so that synthesis SiO2/ZnO core-shell spheres successfully. And observe morphology by FE-SEM and crossection by TEM. The TEM specimen were cut by two-beam FIB. Besides, EDS, XRD and UV-Visible spectroscopy were using for the analysis of composition, crystallization structure, and absorption spectrum, respectively. Experimental results showed that, SiO2spherical surface became smooth after deposition for zinc oxide. The specimen made by FIB more obviously was observed for core-shell distribution by TEM. EDS analysis made us clearly see shell signal with ZnO content, but core signal only is SiO2content. XRD analysis indicated its core-shell sphere signal possessing ZnO content, but UV-Visible absorption spectrometer displayed ZnO has been absorbed in range of UV light, in contrast, it is not absorbed in range of visible light.

scholarly journals Synthesis, Characterization, and Investigation of Visible Light Photocatalytic Activity of C Doped TiO2/CdS Core-Shell Nanocomposite

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Atul B. Lavand ◽  
Yuvraj S. Malghe ◽  
Suraj H. Singh
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Region ◽  
Cds Nanoparticles ◽  
Core Shell ◽  
Visible Absorption ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Uv Visible ◽  
Visible Light Photocatalytic

Carbon (C) doped TiO2/CdS core-shell nanocomposite (C/TiO2/CdS) was synthesized using microemulsion method. Synthesized powder was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and UV-visible spectrophotometery. TEM images reveal that C/TiO2/CdS core-shell heterostructure is successfully prepared with CdS as a core and C doped TiO2 as a shell. UV-visible absorption spectra show that CdS nanoparticles act as a sensitizer and effectively enhance the photoabsorption capacity of C/TiO2/CdS nanocomposite in visible region. Visible light photocatalytic activity of synthesized nanocomposite was evaluated for the degradation of methylene blue. C/TiO2/CdS core-shell nanocomposite exhibits better photocatalytic activity as compared to bare TiO2, CdS, CdS/TiO2, and C doped TiO2.

Optical and Magnetic Studies of Fe3O4/Au Core/Shell Nanocomposites

2019 ◽  
Vol 18 (05) ◽  
pp. 1850033 ◽  
Author(s):  
Al-Sayed A. M. Al-Sherbini ◽  
Gamal El-Ghannam ◽  
Hesham Yehya ◽  
O. Aied Nassef
Keyword(s):  
Shell Structures ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Visible Absorption ◽  
The Core ◽  
Transmission Electron ◽  
Surface Poisoning ◽  
Shell Particles

In this paper, we report the synthesis of Fe3O4 nanoparticles which are resistant to surface poisoning, has been adopted. Fe3O4 nanoparticles have been successfully coated with Au in the form of a shell with different sizes (Fe3O4/Au Core/Shell). Adjustment of the components’ ratio makes the shell thickness of the core/shell particles tunable. Thus, the presented route yields well-defined core/shell structures of different sizes in the range 15–57[Formula: see text]nm with varying the proportion of Au noble metal to Fe3O4 nanoparticles. The UV-Visible absorption spectra, X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) were applied for the characterization of the formed core/shell structures. Moreover, magnetic properties of the core/shell nanocomposites were also studied using Vibrating Sample Magnetometry (VSM).

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