Preparation of surface-modified ZnO quantum dots through an ultrasound assisted sol–gel process

2015 ◽  
Vol 346 ◽  
pp. 111-114 ◽  
Author(s):  
E Moghaddam ◽  
AA Youzbashi ◽  
A Kazemzadeh ◽  
MJ Eshraghi
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Sol Gel Process ◽  
Ultrasound Assisted ◽  
Zno Quantum Dots ◽  
Surface Modified

Photoluminescence of ZnO quantum dots produced by a sol–gel process

2008 ◽  
Vol 30 (8) ◽  
pp. 1233-1239 ◽  
Author(s):  
Debasis Bera ◽  
Lei Qian ◽  
Subir Sabui ◽  
Swadeshmukul Santra ◽  
Paul H. Holloway
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Sol Gel Process ◽  
Zno Quantum Dots

Dual role of the reactant MOH (M=Li, Na or K) in the growth of ZnO quantum dots under a sol–gel process: promoter and inhibitor

RSC Advances ◽  
2016 ◽  
Vol 6 (55) ◽  
pp. 50173-50179 ◽  
Author(s):  
Song Li ◽  
Song Ye ◽  
Tianhua Liu ◽  
Zhuang Guo ◽  
Huiyun Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Dual Role ◽  
Synthesis Process ◽  
Sol Gel Process ◽  
Zno Quantum Dots ◽  
Sol Gel Synthesis

ZnO quantum dots (QDs) with tunable size and photoluminescence can be achieved simply by controlling their growth during the sol–gel synthesis process.

scholarly journals Carbon Quantum Dots Encapsulated Molecularly Imprinted Fluorescence Quenching Particles for Sensitive Detection of Zearalenone in Corn Sample

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 438 ◽  
Author(s):  
Manyu Shao ◽  
Ming Yao ◽  
Sarah De Saeger ◽  
Liping Yan ◽  
Suquan Song
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Sol Gel ◽  
Carbon Quantum Dots ◽  
Detection Range ◽  
Molecularly Imprinted ◽  
Relative Standard ◽  
Sol Gel Process ◽  
One Step ◽  
Optimized Conditions

An eco-friendly and efficient one-step approach for the synthesis of carbon quantum dots (CDs) that encapsulated molecularly imprinted fluorescence quenching particles (MIFQP) and their application for the determination of zearalenone (ZEA) in a cereal sample are described in this study. CDs with high luminescence were first synthesized, and then encapsulated in the silica-based matrix through a non-hydrolytic sol-gel process. The resulting ZEA-imprinted particles exhibited not only an excellent specific molecular recognition of ZEA, but also good photostability and obvious template binding-induced fluorescence quenching. Under the optimized conditions, the fluorescence intensity of MIFQP was inversely proportional to the concentration of ZEA. By validation, the detection range of these fluorescence quenching materials for ZEA was between 0.02 and 1.0 mg L−1, and the detection limit was 0.02 mg L−1 (S/N = 3). Finally, the MIFQP sensor was successfully applied for ZEA determination in corn with recoveries from 78% to 105% and the relative standard deviation (RSD %) was lower than 20%, which suggests its potential in actual applications.

Effect of Cores on Photoluminescence of Hybrid SiO2-Coated CdTe Quantum Dots

2020 ◽  
Vol 20 (9) ◽  
pp. 5478-5485
Author(s):  
Cong Xie ◽  
Yubin Zhao ◽  
Yuxiang Song ◽  
Yingjie Liu ◽  
Yaya Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Stability ◽  
Sol Gel ◽  
Quantum Yields ◽  
Core Shell ◽  
Aqueous Synthesis ◽  
Pl Spectra ◽  
Cdte Qds ◽  
Sol Gel Process ◽  
20 Nm

Compared with conventional semiconductor quantum dots, hybrid SiO2 coated CdTe QDs exhibited high stability, long fluorescent lifetime, high photoluminescence quantum yields, and well biocompatibility. In this paper, CdTe QDs with tunable PL from green to red emitting were prepared by an aqueous synthesis. A sol–gel process resulted in CdTe QDs coated with a hybrid SiO2 shell contained CdS-like clusters to obtain red-shifted PL spectra, increased PL efficiency and high stability. The clusters were formed by the reaction of Cd2+ and S2− ions generated via the decomposition of thioglycolic acid. The clusters around CdTe cores created a core–shell structure which is very similar with traditional semiconductor core–shell QDs. After being coated with a hybrid SiO2 shell, the PL of green-emitting naked CdTe QDs was red-shifted largely (~30 nm) while the PL of yellowemitting CdTe QDs revealed a small red-shifted (~20 nm). Furthermore, The PL of red-emitting naked CdTe QDs was red-shifted much small (less than 10 nm). This phenomenon is ascribed to the change of band gap of CdTe cores with sizes. The red-shift of PL spectra is attributed to the CdS-like clusters around the core rather than the thickness of the hybrid SiO2 shell.

Studies on Optical Properties of CdS/ZnO Quantum Dots Prepared by Sol-Gel Method

2011 ◽  
Vol 364 ◽  
pp. 129-133 ◽  
Author(s):  
Liyana Mohd Lawi Ruhana ◽  
Taqiyuddin Mawardi Ayob Muhammad ◽  
Radiman Shahidan ◽  
Irman Abdul Rahman ◽  
Bohari M. Yamin
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Emission Spectra ◽  
Blue Shift ◽  
Mixture Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Zno Quantum Dots ◽  
Zno Qds

CdS/ZnO quantum dots (QDs) were prepared at a temperature of 293 K by the sol-gel method with Triethanolamine (TEA) as a capping agent. The effect of CdS/ZnO mixture ratio of 1:9, 1:1 and 9:1 on the optical absorption and fluorescence spectra were investigated by UV-Vis and Fluorescence spectroscopy. By increasing ZnO composition, a blue-shift of absorption edge and emission spectra were observed. The band gap for 1:9, 1:1 and 9:1 were found to be 4.13, 3.93 and 3.11 eV, respectively. The morphology of the CdS/ZnO QDs for each mixing ratio was obtained by transmission electron microscope (TEM). The size of the QDs was found to be in the range of 5-10 nm with some agglomerated particles.

Luminescence Properties of Sm3+/Eu3+ Co-Doped ZnO Quantum Dots

2016 ◽  
Vol 16 (4) ◽  
pp. 3597-3601
Author(s):  
Fengyi Liu ◽  
Hong Li ◽  
Yajing Hu ◽  
Na Jin ◽  
Yun Mou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Spherical Shape ◽  
Hexagonal Wurtzite Structure ◽  
Luminescence Properties ◽  
Transmission Electron ◽  
Doped Zno ◽  
Zno Quantum Dots ◽  
Zno Qds ◽  
Co Doped

In order to improve luminescence properties of semiconductor ZnO quantum dots (QDs), Sm3+/Eu3+ co-doped ZnO QDs have been controllably synthesized by sol–gel method in this paper. ZnO QDs have a spherical shape with mean diameter at about 5–6 nm, which was characterized by high-resolution transmission electron microscopy (HRTEM). ZnO QDs have hexagonal wurtzite structure with parts of Sm3+ and Eu3+ incorporated into the lattice, which was demonstrated by X-ray Diffraction (XRD). Luminescence properties at room temperature (RT) of different amount of Sm3+ and 2 mol% Eu3+ doped ZnO QDs were examined in-depth by optical spectra. In contrast to the Pr3+/Eu3+ co-doped fluorescent performance researched in our previous study, the photoluminescence (PL) spectra indicates the unique luminescence properties of Sm3+/Eu3+ co-doped ZnO QDs. In addition, fluorescence lifetimes were obtained to illustrate the luminous mechanism.

Enhanced ultraviolet emission and optical properties in polyvinyl pyrrolidone surface modified ZnO quantum dots

2001 ◽  
Vol 90 (9) ◽  
pp. 4489-4493 ◽  
Author(s):  
C. L. Yang ◽  
J. N. Wang ◽  
W. K. Ge ◽  
L. Guo ◽  
S. H. Yang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Polyvinyl Pyrrolidone ◽  
Ultraviolet Emission ◽  
Zno Quantum Dots ◽  
Surface Modified
Sign in / Sign up

Export Citation Format

Share Document