Effect of Aluminum on the Formation of Silver Metal Quantum Dots in Sol–Gel Derived Alumino-Silicate Glass Film

2006 ◽  
Vol 6 (11) ◽  
pp. 3399-3403 ◽  
Author(s):  
Bok Hyeon Kim ◽  
Dong Hoon Son ◽  
Seongmin Ju ◽  
Chaehwan Jeong ◽  
Seongjae Boo ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Silicate Glass ◽  
Glass Structure ◽  
Sol Gel ◽  
Glass Plate ◽  
Aluminum Concentration ◽  
Glass Film ◽  
Aluminum Ions ◽  
Alumino Silicate ◽  
Silver Metal

The effect of aluminum incorporation on silver metal quantum dots formation in the alumino-silicate glass film processed by sol–gel process was investigated. The sol–gel derived glass was coated onto the silica glass plate by spin coating with the mixture solution of tetraethyl orthosilicate (TEOS), C2H5OH, H2O, AgNO3, Al(NO3)3·9H2O, and HNO3 with the molar ratios of Ag/Si = 0.12 and Al/Si varying from 0 to 0.12. The formation of the silver metal quantum dots was confirmed by the measurements of the UV/VISoptical spectra, the X-ray diffraction patterns, and the transmission electron microscope images. While the radius of silver metal quantum dots increased with the increase of aluminum concentration, the concentration of the silver metal quantum dots decreased. The formation of the silver metal quantum dots was found strongly suppressed by incorporation of aluminum ions in the glass. The change in the glass structure due to the aluminum incorporation was investigated by the analysis of the Raman spectra. The silver ions in the glass contributed to form stable (Al:Ag)O4 tetrahedra by pairing with aluminum ions and thus clustering of silver metal quantum dots was hindered.

Excitonic quasimolecules containing of two quantum dots

2016 ◽  
pp. 4024-4028 ◽  
Author(s):  
Sergey I. Pokutnyi ◽  
Wlodzimierz Salejda
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Exchange Interaction ◽  
Coulomb Interaction ◽  
Silicate Glass ◽  
Glass Matrix ◽  
Silicate Glass Matrix

The possibility of occurrence of the excitonic  quasimolecule formed of spatially separated electrons and holes in a nanosystem that consists  of  CuO quantum dots synthesized in a silicate glass matrix. It is shown that the major contribution to the excitonic quasimolecule binding energy is made by the energy of the exchange interaction of electrons with holes and this contribution is much more substantial than the contribution of the energy of Coulomb interaction between the electrons and holes.

scholarly journals Carbon Nitride Quantum Dots Modified TiO2 Inverse Opal Photonic Crystal for Solving Indoor VOCs Pollution

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 464
Author(s):  
Jie Yu ◽  
Angel Caravaca ◽  
Chantal Guillard ◽  
Philippe Vernoux ◽  
Liang Zhou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Nitride ◽  
Sol Gel ◽  
Green Energy ◽  
Inverse Opal ◽  
Oxidation Reactions ◽  
Composite Photocatalyst ◽  
Colloidal Photonic Crystals ◽  
Inverse Opal Structure

Indoor toxic volatile organic compounds (VOCs) pollution is a serious threat to people’s health and toluene is a typical representative. In this study, we developed a composite photocatalyst of carbon nitride quantum dots (CNQDs) in situ-doped TiO2 inverse opal TiO2 IO for efficient degradation of toluene. The catalyst was fabricated using a sol-gel method with colloidal photonic crystals as the template. The as-prepared catalyst exhibited excellent photocatalytic performance for degradation of toluene. After 6 h of simulated sunlight irradiation, 93% of toluene can be converted into non-toxic products CO2 and H2O, while only 37% of toluene is degraded over commercial P25 in the same condition. This greatly enhanced photocatalytic activity results from two aspects: (i) the inverse opal structure enhances the light harvesting while providing adequate surface area for effective oxidation reactions; (ii) the incorporation of CNQDs in the framework of TiO2 increases visible light absorption and promotes the separation of photo-generated charges. Collectively, highly efficient photocatalytic degradation of toluene has been achieved. In addition, it can be expanded to efficient degradation of organic pollutants in liquid phase such as phenol and Rhodamine B. This study provides a green, energy saving solution for indoor toxic VOCs removal as well as for the treatment of organic wastewater.

Role of vanadium oxide on the lithium silicate glass structure and properties

2021 ◽  
Author(s):  
Anuraag Gaddam ◽  
Amarnath R. Allu ◽  
Hugo R. Fernandes ◽  
George E. Stan ◽  
Catalin C. Negrila ◽  
...  
Keyword(s):  
Vanadium Oxide ◽  
Silicate Glass ◽  
Glass Structure ◽  
Lithium Silicate ◽  
Structure And Properties ◽  
Lithium Silicate Glass

Preparation and non-linear optical properties of CdS quantum dots in Na2O-B2O3-SiO2 glasses by the sol-gel technique

1996 ◽  
Vol 31 (2) ◽  
pp. 423-430 ◽  
Author(s):  
T. Takada ◽  
J. D. Mackenzie ◽  
M. Yamane ◽  
K. Kang ◽  
N. Peyghambarian ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Sol Gel ◽  
Cds Quantum Dots ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Gel Technique ◽  
Linear Optical

scholarly journals Preparation of Glass Plate-Supported Nanostructure ZnO Thin Film Deposited by Sol-Gel Spin-Coating Technique and Its Photocatalytic Degradation to Monoazo Textile Dye

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Hossein Habibi ◽  
Mohammad Khaledi Sardashti
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Photocatalytic Degradation ◽  
Spin Coating ◽  
Sol Gel ◽  
Glass Plate ◽  
Zno Thin Films ◽  
Visible Range ◽  
Textile Dye ◽  
Axis Orientation

Glass plate-supported nanostructure ZnO thin films were deposited by sol-gel spin coating. Films were preheated at275∘Cfor 10 minutes and annealed at 350, 450, and550∘Cfor 80 minutes. The ZnO thin films were transparent ca 80–90% in visible range and revealed that absorption edges at about 370 nm. Thec-axis orientation improves and the grain size increases which was indicated by an increase in intensity of the (002) peak at34.4∘in XRD corresponding to the hexagonal ZnO crystal. The photocatalytic degradation of X6G an anionic monoazo dye, in aqueous solutions, was investigated and the effects of some operational parameters such as the number of layer and reusability of ZnO nanostructure thin film were examined. The results showed that the five-layer coated glass surfaces have a very high photocatalytic performance.

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