scholarly journals Fabrication of Durable Ordered Ta2O5 Nanotube Arrays Decorated with Bi2S3 Quantum Dots

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1347 ◽  
Author(s):  
Baluk ◽  
Kobylański ◽  
Lisowski ◽  
Trykowski ◽  
Klimczuk ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Anodic Oxidation ◽  
High Photocatalytic Activity ◽  
Nanotube Arrays ◽  
Silar Method ◽  
Tem Analysis ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Layer Adsorption ◽  
Degradation Reaction

One of the most important challenges in the fabrication of ordered tantalum pentaoxide (Ta2O5) nanotube arrays (NTs) via the electrochemical method is the formation of nanotubes that adhere well to the Ta substrate. In this paper, we propose a new protocol that allows tight-fitting Ta2O5 nanotubes to be obtained through the anodic oxidation of tantalum foil. Moreover, to enhance their activity in the photocatalytic reaction, in this study, they have been decorated by nontoxic bismuth sulfide (Bi2S3) quantum dots (QDs) via a simple successive ionic layer adsorption and reaction (SILAR) method. Transmission electron microscopy (TEM) analysis revealed that quantum dots with a size in the range of 6–11 nm were located both inside and on the external surfaces of the Ta2O5 NTs. The effect of the anodization time and annealing conditions, as well as the effect of cycle numbers in the SILAR method, on the surface properties and photoactivity of Ta2O5 nanotubes and Bi2S3/Ta2O5 composites have been investigated. The Ta2O5 nanotubes decorated with Bi2S3 QDs exhibit high photocatalytic activity in the toluene degradation reaction, i.e., 99% of toluene (C0 = 200 ppm) was degraded after 5 min of UV-Vis irradiation. Therefore, the proposed anodic oxidation of tantalum (Ta) foil followed by SILAR decorating allows a photocatalytic surface, ready to use for pollutant degradation in the gas phase, to be obtained.

scholarly journals Synthesis and Surface Modification of Biocompatible Water Soluble Core-Shell Quantum Dots

2014 ◽  
Vol 879 ◽  
pp. 184-190 ◽  
Author(s):  
Samsulida Abd. Rahman ◽  
Nurhayati Ariffin ◽  
Nor Azah Yusof ◽  
Jaafar Abdullah ◽  
Zuhana Ahmad Zubir ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Average Particle Size ◽  
Fluorescence Emission ◽  
Water Soluble ◽  
Average Particle ◽  
Silar Method ◽  
Mercaptosuccinic Acid ◽  
Transmission Electron ◽  
Layer Adsorption ◽  
Capping Ligands

In this study, the applications of CdSe/ZnS quantum dots (QDs) and its role in advanced sensings has been explored. The CdSe/ZnS was synthesized by using hot injection method with the shell ZnS layer was made using successive ionic layer adsorption and reaction (SILAR) method. The morphology of the CdSe/ZnS QDs was studied using Transmission Electron Microscope (TEM) and the average particle size was in 10-12 nm range. The prepared QDs were optically characterized using spectrofluorescence and strong emission was observed at 620 nm. Comparison of the fluorescence emissions of CdSe/ZnS capped with various capping ligands such as L-cysteine, thioglycolic acid (TGA), mercaptopropionic acid (MPA), mercaptosuccinic acid (MSA) and mercaptoundecanoic acid (MUA) were studied. The CdSe/ZnS capped with TGA gave the strongest fluorescence emission compared to others.

Improving photoelectrochemical performance of highly-ordered TiO2 nanotube arrays with cosensitization of PbS and CdS quantum dots

RSC Advances ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 8118-8126 ◽  
Author(s):  
Xiaojiao Zhang ◽  
Min Zeng ◽  
Jiawei Zhang ◽  
Aimin Song ◽  
Shiwei Lin
Keyword(s):  
Quantum Dots ◽  
Tio2 Nanotube Arrays ◽  
Tio2 Nanotube ◽  
Nanotube Arrays ◽  
Cds Quantum Dots ◽  
Photoelectrochemical Performance ◽  
Silar Method ◽  
Layer Adsorption ◽  
Ionic Layer

PbS and CdS quantum dots (QDs) were deposited on TiO2 nanotube arrays (TNTAs) by a sonication-assisted successive ionic layer adsorption and reaction (S-SILAR) method.

scholarly journals Optical Studies of Organically Functionalized Mn doped ZnS Quantum Dots

2021 ◽  
Vol 33 (12) ◽  
pp. 2972-2976
Author(s):  
Anju Bala ◽  
Rajeev Sehrawat ◽  
Renu Bala ◽  
Ashutosh Dixit
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Emission Spectra ◽  
Blue Shift ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Uv Visible ◽  
Mn Doped

Organically functionalized manganese doped zinc sulfide (ZnS/Mn) quantum dots were prepared by simple chemical method with polypyrrole (PPy) used as a capping agent. Prepared quantum dots were characterized with Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction microscope (XRD), UV-visible spectroscopy and photoluminescence spectroscopy. Crystalline size of PPy capped ZnS/Mn quantum dots for various concentrations of PPy were approximate 2 nm as analyzed by XRD and TEM analysis. The absorption spectra revealed the occurrence of a blue shift in the peak of absorption and an increase in the band gap value due to the quantum confinement effect. FTIR spectroscopy confirmed that shifting of broad peak at 2335.8 cm–1 was due to S-H stretching vibrations, which confirmed interaction of hydrogen and sulphur in ZnS/Mn/PPy nanocomposites. Uncapped ZnS/Mn and PPy capped ZnS/Mn quantum dots reveal the effective photoluminescence emission spectra in the range of 300-700 nm. With increase the value of capping agent in ZnS/Mn quantum dots, photoluminescence spectra going to red shifting. The photoluminescence properties of the organically functionalized ZnS nanoparticles are favourable for the application in optoelectronic devices.

scholarly journals Room-temperature solution-phase epitaxial nucleation of PbS quantum dots on rutile TiO2 (100)

2020 ◽  
Vol 2 (1) ◽  
pp. 377-383 ◽  
Author(s):  
Stefan Kraus ◽  
Mischa Bonn ◽  
Enrique Cánovas
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Solution Phase ◽  
Silar Method ◽  
Rutile Tio2 ◽  
Layer Adsorption ◽  
Temperature Solution ◽  
Pbs Quantum Dots ◽  
Ionic Layer

We demonstrate epitaxial nucleation of QDs onto titania by the successive ionic layer adsorption and reaction (SILAR) method at room temperature.

scholarly journals The Synthesis of Highly Fluorescent Carbon Quantum Dots from Tartaric Acid

2020 ◽  
Vol 10 (6) ◽  
pp. 7337-7342
Keyword(s):  
Quantum Dots ◽  
Tartaric Acid ◽  
Low Cost ◽  
Photovoltaic Cell ◽  
Carbon Quantum Dots ◽  
Fluorescent Properties ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Bio Compatibility ◽  
Fluorescent Carbon

Carbon quantum dots (C-dots) have attracted tremendous interest because of their advantageous characteristics of cost-effectiveness and fluorescent nature. In this study, we developed a simple, economical, and effective method for the green synthesis of fluorescent carbon quantum dots using low-cost hydrothermal treatment of Tartaric acid as a carbon source. The as-synthesized C-dots were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV–Vis absorption spectroscopy, Spectrofluorophotometry, Fourier transform infrared spectroscopy (FT-IR). The synthesized C-dots possess stable fluorescent properties, good, bio-compatibility, and high quantum yield. The C-dots are highly crystalline, with longitudinal dimensions of 3.128 ± 0.17 nm. The XRD and TEM analysis indicates that the synthesized C-dots have a nearly spherical morphology and narrow size distribution. The results suggest that the proposed C-dots could be utilized for photovoltaic cell, bioimaging, drug delivery, and biosensor applications.

scholarly journals The Investigation of Microwave-Assisted Greener Synthesis of Ag/Ti/Zn Trimetallic Nanoparticles and Carbon Quantum Dots Nanocomposites in the Application of Solar Cell

2021 ◽  
Vol 11 (1) ◽  
pp. 3102-3110
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Solar Cell ◽  
Carbon Quantum Dots ◽  
Copper Plate ◽  
Tem Analysis ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Greener Synthesis

In this communication, we report a greener microwave method for synthesizing Ag/Ti/Zn trimetallic nanoparticles and carbon quantum dots nanocomposites (Ag/Ti/Zn TNPs and CQDs NCs). The morphology, topography, and size of the Ag/Ti/Zn TNPs and CQDs nanocomposites were determined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. The optical properties of the as-synthesized Ag/Ti/Zn TNPs and CQDs NCs were examined using UV–Vis spectroscopy and bandgap analysis. Finally, the Ag/Ti/Zn TNPs and CQDs NCs were fabricated by microwave-assisted greener synthesis, which was used as a photosensitizer, the copper plate as a counter electrode, and polysulfide as an electrolyte was assembled into the solar cell. The natural pigments extracted from the fruit of Solanum lycopersicium extract were used in Ag/Ti/Zn TNPs and CQDs NCs based solar cells. The as-fabricated solar cell's conversion efficiency was 5.47% with a Voc of 0.74 V, Jsc of 12.1 mA/cm2, and an FF of 0.60. Thus, this study highlights that the use of Ag/Ti/Zn TNPs and CQDs NCs has the great potential to be used as a photosensitizer.

Enhanced Catalytic Activities of TiO2 Nanotube Arrays Co-Sensitized with Pt/CdS/ZnS via Electrodeposition and Successive Ionic Layer Adsorption and Reaction (SILAR) Method Approach

2021 ◽  
Vol 21 (12) ◽  
pp. 6111-6119
Author(s):  
Van Manh Nguyen ◽  
Trinh Tung Ngo ◽  
Thi Thu Trang Bui ◽  
Thi Thanh Hop Tran ◽  
The Huu Nguyen ◽  
...  
Keyword(s):  
Visible Region ◽  
Passive Layer ◽  
Nanotube Arrays ◽  
Silar Method ◽  
Nanotube Array ◽  
Environmental Treatment ◽  
Layer Adsorption ◽  
Photon Conversion ◽  
Photocatalytic Material ◽  
Decomposition Efficiency

In this work, we have synthesized a nanocomposite ZnS/CdS/Pt/TiO2 nanotube arrays (denoted ZCP-NTAs). Firstly, TiO2 nanotube array (NTAs) material was fabricated by the anodic method of a titanium plate in an electrolyte solution containing 0.35 M NaHSO4 and 0.24 M NaF and incubated in the air at 500 ºC for 2 hours. After that, pulsed electrodeposition technology was used to decorate platinum nanoparticles (denoted as Pt NPs) onto the surface of TiO2 nanotubes to form P-NTAs photoelectrodes. Then, the SILAR method is used to deposition CdS quantum dots (symbolized as CdS QDs) on the surface of P-NTAs to form CP-NTAs material. Finally, by the SILAR method, a ZnS passive layer that protects against optical corrosion and inhibits recombination of e−/h+ pairs was coated onto the CP-NTAs to form ZCP-NTAs material. As-prepared ZCP-NTAs photocatalytic material has good absorbability of light in the visible region with light absorption wavelength up to 608 nm, photon conversion efficiency up to 5.32% under light intensity AM1.5G, and decomposition efficiency of 10 mg L−1 methyl orange (MO) in 120 minutes reached 91.50%. This material promises to bring high application ability in the photocatalytic field applied for environmental treatment and other applications.

Study on Preparation of CdS Quantum Dots for Dye Sensitized Solar Cells

2014 ◽  
Vol 1070-1072 ◽  
pp. 608-611
Author(s):  
Xiang Yu Wan ◽  
Xing An Mei ◽  
Yong Hong Tian ◽  
Da Hai Xu ◽  
Yan Xiong
Keyword(s):  
Quantum Dots ◽  
Solar Cell ◽  
Quantum Dot ◽  
High Efficiency ◽  
Dye Sensitized Solar Cells ◽  
Cds Quantum Dots ◽  
Silar Method ◽  
Dye Sensitized ◽  
Layer Adsorption ◽  
Sensitized Solar Cells

Quantum dot sensitized solar cell (QDSSC) has a potential high efficiency as the third generation solar cell, on account of the excellent performance of quantum dots. CdS is one of the most widely used quantum dot of QDSSCs, hence the optimization of its preparation process is extremely important. CdS quantum dots prepared in aqueous or alcohol on TiO2 film by successive ionic layer adsorption and reaction (SILAR) method are investigated and alcohol is found to be better than water as the precursor solvent.

Synthesis of SnSe quantum dots by successive ionic layer adsorption and reaction (SILAR) method for efficient solar cells applications

Solar Energy ◽  
2020 ◽  
Vol 199 ◽  
pp. 570-574 ◽  
Author(s):  
D. Kishore Kumar ◽  
Jan Loskot ◽  
Jan Kříž ◽  
Nick Bennett ◽  
Hari M. Upadhyaya ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Silar Method ◽  
Layer Adsorption ◽  
Ionic Layer

scholarly journals CdTeO3Deposited Mesoporous NiO Photocathode for a Solar Cell

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Chuan Zhao ◽  
Xiaoping Zou ◽  
Sheng He
Keyword(s):  
Quantum Dots ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Silar Method ◽  
Layer Adsorption ◽  
P Type ◽  
Nio Films ◽  
Ionic Layer

Semiconductor sensitized NiO photocathodes have been fabricated by successive ionic layer adsorption and reaction (SILAR) method depositing CdTeO3quantum dots onto mesoscopic NiO films. A solar cell using CdTeO3deposited NiO mesoporous photocathode has been fabricated. It yields a photovoltage of 103.7 mV and a short-circuit current density of 0.364 mA/cm2. The incident photon to current conversion efficiency (IPCE) value is found to be 12% for the newly designed NiO/CdTeO3solar cell. It shows that the p-type NiO/CdTeO3structure could be successfully utilized to fabricate p-type solar cell.

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