Preparation ZnS Quantum Dots via Water-Phase Synthesis Method

2013 ◽  
Vol 706-708 ◽  
pp. 230-233
Author(s):  
Wei Liu ◽  
Xian Lan Chen ◽  
Ju Cheng Zhang ◽  
Yun Hui Long ◽  
Ling Shi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ph Value ◽  
Synthesis Method ◽  
Emission Spectra ◽  
Water Phase ◽  
Complexing Agents ◽  
Complex Ions ◽  
Aqueous Synthesis ◽  
Phase Synthesis ◽  
Optimal Reaction

With water as the medium, PVP as stabilizer and ammonia as complexing agents and adjusting pH value of the solution, we report an all-aqueous synthesis of highly photoluminescent and stable ZnS quantum dots (QDs) by water-phase synthesis reaction between ZnCl2 and NaS at different temperatures and times. The optimal reaction conditions of PVP-capped ZnS QDs were obtained through experiment as follows: the concentration ZnCl2 and NaS solution both are 1 mM, (PVP):(ZnCl2) = 0.0167 (v/v), (NH3):(ZnCl2)=1:300 (v/v), the optimal reaction temperature is 40 °C, the optimal reaction time is 30 min. With ammonia as complexing agents, Zn(OH)2 can dissolve in ammonia and form to complex ions ((Zn(NH3)4)2+), which make Zn2+ release slowly to control the nucleus growth rate of ZnS, thus obtain small size of nanoparticles. The fluorescence spectra shows that the emission peaks of ZnS QDs around ~395 nm and ~470 nm on the emission spectra, which are consistent with literatures, so nano-ZnS QDs was synthesized successfully in this paper.

Hydrothermal-Based Synthesis of CdS/ZnO Quantum Dots

2014 ◽  
Vol 875-877 ◽  
pp. 362-365
Author(s):  
Xian Lan Chen ◽  
Wei Liu ◽  
Ju Cheng Zhang ◽  
Qing Shan Pan ◽  
Du Shu Huang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ph Value ◽  
Synthesis Method ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Hydrothermal Condition ◽  
Zinc Ion ◽  
Fluorescence Emission Spectra ◽  
Zno Quantum Dots ◽  
Zno Qds

In this article, the CdS and CdS/ZnO quantum dots (QDs) were prepared by hydrothermal synthesis method. The optimal reaction conditions of CdS/ZnO QDs were obtained through experiment as follows: the pH value of solution is 10.0, the reaction temperature is 140 °C and reaction time is 24 h. While the pH value is up to10.0, Zinc ion exist in solution with Zn (OH)2 and Zn (OH)42-, which is apt to adsorb on the surface of CdS, and form to ZnO shell under the hydrothermal condition, so CdS/ZnO QDs are synthesized successfully. The photographic images and fluorescence emission spectra results showed that the colour and the peak position of fluorescence spectra of CdS/ZnO QDs is consistent with literatures, which confirming the feasibility of this method.

scholarly journals Solid-Phase Preparation of Al-TiO2 for Efficient Separation of Bioderived Product Danshensu

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Fei Chang ◽  
Zhong Bing He ◽  
Quan Zhou
Keyword(s):  
Solid Phase Synthesis ◽  
Ph Value ◽  
Solid Phase ◽  
Synthesis Method ◽  
Uv Spectrophotometry ◽  
Elution Volume ◽  
Phase Synthesis ◽  
Adsorption Time ◽  
Sample Concentration ◽  
Efficient Separation

Four kinds of Al-TiO2 solid samples with different Ti/Al ratios of 1 : 0.1, 1 : 0.09, 1 : 0.07, and 1 : 0.05 were synthesized via a solid-phase synthesis method and characterized by XRD, SEM, EDS, BET, and other techniques. The prepared solids were used for separation of the bioderived product danshensu, the content of which was determined by UV spectrophotometry. Moreover, the effects of extract concentration, PH value, adsorption time, and ethanol elution volume were investigated. The results showed that these Al-TiO2 samples had good adsorption and desorption ability. Especially, the solid Al-TiO2 with a Ti/Al ratio of 1 : 0.05 is more suitable for the separation of danshensu, exhibiting a higher adsorption (77.70%) under 2 h adsorption time and pH = 3; meanwhile, the high desorption rate (70.29%）was received under 80% ethanol and the sample concentration of 3.0 mg/mL.

scholarly journals Quantum Dots: Method of Preparation and Biological Application

2019 ◽  
Vol 9 (4-s) ◽  
pp. 670-672 ◽  
Author(s):  
Amol Gomase ◽  
Sagar Sangale ◽  
Akshay Mundhe ◽  
Pravin Gadakh ◽  
Vikrant Nikam
Keyword(s):  
Drug Delivery ◽  
Quantum Dots ◽  
Chemical Synthesis ◽  
Synthesis Method ◽  
Biological Application ◽  
Semiconductor Crystal ◽  
Phase Synthesis ◽  
Light Emitting ◽  
Inorganic Semiconductor ◽  
Conductive Property

Quantum dots are inorganic semiconductor crystal of nanometer size which having distinctive conductive property depend on its size & shape. After administration of quantum dots parentally they identify target and bound them. Also quantum dots having light emitting property depend on size & shape. Quantum dots are prepared by chemical synthesis method include both organic & water phase synthesis & also by top- bottom approach. Tumor cell targeting & detection of pathogen & toxin are the main application of quantum dots & also in targeting drug delivery system. This review provides the overview of method of preparation of quantum dots & its biological application. Keywords: Quantum dot, targeting drug delivery, biological application

Photochemical Events during the Photosensitization of Hypocrellin A on ZnS Quantum Dots

2012 ◽  
Vol 581-582 ◽  
pp. 574-577 ◽  
Author(s):  
Wei Liu ◽  
Xian Lan Chen ◽  
La Shi Yang ◽  
Ju Cheng Zhang ◽  
Ping Yi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Strong Interaction ◽  
Organic Dyes ◽  
Synthesis Method ◽  
Raw Material ◽  
Phase Synthesis ◽  
Hypocrellin A ◽  
Optimum Ph

Hypocrellin A is organic dyes with more superior visible light performance, which has resistant tumor activity and becomes widely accepted. In this paper, acetone is used as solvent to extract, separate and purify the hypocrellin A. With ZnCl2 and Na2S as raw material, ZnS Quantum dots (QDs) were prepared by water-phase synthesis method under the role of the magnetic stirrer. Fluorescence detection results showed that the optimum pH of the ZnS QDs and HA solution close to neutral (6.86). The fluorescence quenching of hypocrellin A is most obvious as the ZnS QDs was added, because of the strong interaction was generated between HA and ZnS QDs, resulting in the fluorescence quenching.

Water Phase Synthesis Method of CuInS2 Nanoparticles and Its Application for Photovoltaic Device

2020 ◽  
Vol MA2020-02 (15) ◽  
pp. 1444-1444
Author(s):  
Hideyuki Takahashi ◽  
Mitsuo Goto ◽  
Shun Yokoyama
Keyword(s):  
Synthesis Method ◽  
Photovoltaic Device ◽  
Water Phase ◽  
Phase Synthesis

scholarly journals Zeolite NaP1 Functionalization for the Sorption of Metal Complexes with Biodegradable N-(1,2-dicarboxyethyl)-D,L-aspartic Acid

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2518
Author(s):  
Dorota Kołodyńska ◽  
Yongming Ju ◽  
Małgorzata Franus ◽  
Wojciech Franus
Keyword(s):  
Experimental Data ◽  
Aspartic Acid ◽  
Ph Value ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Modified Zeolite ◽  
X Ray ◽  
Slow Release Fertilizers ◽  
Pseudo Second Order

The possibility of application of chitosan-modified zeolite as sorbent for Cu(II), Zn(II), Mn(II), and Fe(III) ions and their mixtures in the presence of N-(1,2-dicarboxyethyl)-D,L-aspartic acid, IDHA) under different experimental conditions were investigated. Chitosan-modified zeolite belongs to the group of biodegradable complexing agents used in fertilizer production. NaP1CS as a carrier forms a barrier to the spontaneous release of the fertilizer into soil. The obtained materials were characterized by Fourier transform infrared spectroscopy (FTIR); surface area determination (ASAP); scanning electron microscopy (SEM-EDS); X-ray fluorescence (XRF); X-ray diffraction (XRD); and carbon, hydrogen, and nitrogen (CHN), as well as thermogravimetric (TGA) methods. The concentrations of Cu(II), Zn(II), Mn(II), and Fe(III) complexes with IDHA varied from 5–20 mg/dm3 for Cu(II), 10–40 mg/dm3 for Fe(III), 20–80 mg/dm3 for Mn(II), and 10–40 mg/dm3 for Zn(II), respectively; pH value (3–6), time (1–120 min), and temperature (293–333 K) on the sorption efficiency were tested. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption models were applied to describe experimental data. The pH 5 proved to be appropriate for adsorption. The pseudo-second order and Langmuir models were consistent with the experimental data. The thermodynamic parameters indicate that adsorption is spontaneous and endothermic. The highest desorption percentage was achieved using the HCl solution, therefore, proving that method can be used to design slow-release fertilizers.

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