EFFECT OF OXYGEN ON SIZE-CONTROLLED SYNTHESIS OF CdSe QDs

Unique properties of quantum dots (QDs) are controlled by their customizable particle sizes which can be engineered to suit local need. One-pot organometallic injection synthesis of cadmium selenide (CdSe) QDs is reported. The operation started with the injection of a week old selenium (Se) precursor into a boiling non-coordinating octadecene (ODE) at 195oC resulting in the formation of monodispersed size tunable CdSe QDs with discrete homogeneous nucleation. Differences in the injection and withdrawal time of the sample resulted to the dissimilarity in the shape, size and the opto-electronic properties of the QDs. The effect of oxygen on the synthesized CdSe QDs was studied by exposing freshly prepared sample to atmospheric oxygen for 206 days. The samples were characterized using optical absorption spectroscopy (UV-vis), optical photoluminescence (PL), X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM), electron dispersive X-ray (EDX) X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS). Noticeable deformation on the size, shape and the crystalline orientation of the CdSe QDs were observed on the oxygen-interacted sample.Although the synthesis method is safe and produced good quality CdSe QDs, the interaction of the sample with oxygen degrades their opto-electronic quality.

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Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

Molecules ◽

10.3390/molecules26030661 ◽

2021 ◽

Vol 26 (3) ◽

pp. 661

Author(s):

Zhiwei Ying ◽

Xinwei Chen ◽

He Li ◽

Xinqi Liu ◽

Chi Zhang ◽

...

Keyword(s):

Electron Microscopy ◽

Methylene Blue ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

Urban Pollution ◽

Maximum Adsorption Capacity ◽

One Pot ◽

Average Pore ◽

X Ray ◽

Isotherm Equation

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.

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Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽

10.3390/catal10060640 ◽

2020 ◽

Vol 10 (6) ◽

pp. 640

Author(s):

Hideaki Sasaki ◽

Keisuke Sakamoto ◽

Masami Mori ◽

Tatsuaki Sakamoto

Keyword(s):

Electron Microscopy ◽

Solid Solution ◽

Solid Solutions ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Co Precipitation ◽

Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

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One-pot microwave assisted approach for synthesis of CdSe/CdS core-shell quantum dots (QDs) and investigating optical properties

Modern Physics Letters B ◽

10.1142/s0217984916500743 ◽

2016 ◽

Vol 30 (07) ◽

pp. 1650074 ◽

Cited By ~ 7

Author(s):

M. Molaei ◽

F. Salari Bardsiri ◽

A. R. Bahador ◽

M. Karimipour

Keyword(s):

Core Shell ◽

Heat Sensitivity ◽

X Ray Diffraction ◽

Cdse Qds ◽

One Pot ◽

X Ray ◽

Microwave Assisted ◽

Transmission Electron ◽

Core Shell Structure ◽

Microwave Assisted Method

In this work, CdSe QDs were synthesized using a microwave assisted method and chemical reaction between NaHSe, CdSO4 at the presence of TGA as capping molecule. Thereafter without CdSe extraction, CdS shell was grown subsequently around CdSe cores by a reaction based on the heat sensitivity of Na2S2O3 dissociation. Synthesized QDs were characterized by means of X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV–Vis and photoluminescence (PL) spectroscopy. All of these analyzes confirmed formation of CdSe QDs and successfully growth of CdS shell on surface of CdSe to forming CdSe/CdS core-shell structure.

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One Step Synthesis of Graphene-Like Structures by Carbonization of some Carbohydrates in Molten Salt Media

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.59.166 ◽

2019 ◽

Vol 59 ◽

pp. 166-179 ◽

Cited By ~ 1

Author(s):

Betül Gürünlü ◽

Mahmut Bayramoğlu

Keyword(s):

Molten Salt ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

X Ray Diffraction ◽

X Ray ◽

Hummers Method ◽

Environmental Friendly ◽

One Step ◽

Xrd Patterns ◽

Molten Salt System

Graphene is one of the most promising materials discovered in last years. It is usually synthesized by Hummers’ method requiring the usage of many chemicals. As an alternative to traditional methods, in this study a bottom-up synthesis method was developed from various saccharides such as starch, mannose, cellulose, fructose, arabinose, and xylose by carbonization at 600 °C to 800 °C in LiCl/KCl molten salt system. The proposed method is environmental friendly and economic. Graphene yields at 600 °C are higher than at 800 °C. Graphene products give peak at 2θ = 23° on the X-Ray Diffraction (XRD) patterns. As the temperature is increased, amorph structure is observed on the XRD patterns. Raman spectroscopy results show that intensity of D band peak over intensity of G band peak (ID/IG) values of graphene products synthesized from arabinose and cellulose at 600 °C, graphene from arabinose synthesized at 800 °C are 0.76, 0.65 and 0.85 respectively, which show that these products are few-layered. According to X-ray photoelectron spectroscopy (XPS) results, graphene products synthesized at 600 °C have higher carbon content than those synthesized at 800 °C.

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Organic Nanosynthesis of Ancient Windmill-like Window Gridarenes at Molecular Scale

10.26434/chemrxiv.6729113.v1 ◽

2018 ◽

Author(s):

Ying Wei ◽

Quanyou Feng ◽

Hui Liu ◽

Xiuling Wang ◽

Dongqing Lin ◽

...

Keyword(s):

Main Product ◽

Synthesis Method ◽

Synthetic Method ◽

X Ray Diffraction ◽

One Pot ◽

X Ray ◽

H Nmr ◽

Cyclization Process ◽

Molecular Scale ◽

Insight Into

We focus on another kind of square-type unit nanogrids with starlike divergent extensibility. As a result, square windmill-like nanogrid WG4 have been successfully synthesized by two different kinds of fluorene-based nanosynthons, namely I-shape nanosynthon and L-shape nanosynthon synthesis method. Besides WG4, triangle and hexagon windmill-like nanogrids (WG3 and WG5) are also obtained via one-pot nanosynthesis of I-shape nanosynthon with WG3 as the main product. For the L-shape nanosynthon synthetic method, the cyclization process possesses higher selectivity, resulting to an excellent yield for WG4. In addition, two stereoisomers of the triangle nanogrids, cis-trans-WG3 and cis-cis-WG3, were separated and characterized from the single-crystal X-ray diffraction and 1H NMR analyses for getting insight into the configuration of the triangle nanogrids with the skeleton planarization for the trans-configuration and deplanarization for the cis-configuration.

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Organic Nanosynthesis of Ancient Windmill-like Window Gridarenes at Molecular Scale

10.26434/chemrxiv.6729113 ◽

2018 ◽

Author(s):

Ying Wei ◽

Quanyou Feng ◽

Hui Liu ◽

Xiuling Wang ◽

Dongqing Lin ◽

...

Keyword(s):

Main Product ◽

Synthesis Method ◽

Synthetic Method ◽

X Ray Diffraction ◽

One Pot ◽

X Ray ◽

H Nmr ◽

Cyclization Process ◽

Molecular Scale ◽

Insight Into

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Novel Route to Obtain Carbon Self-Doped TiO2 Mesoporous Nanoparticles as Efficient Photocatalysts for Environmental Remediation Processes under Visible Light

Materials ◽

10.3390/ma12203349 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3349 ◽

Cited By ~ 1

Author(s):

Pablo A. Ochoa Rodríguez ◽

Tamara B. Benzaquén ◽

Gina A. Pecchi ◽

Sandra G. Casuscelli ◽

Verónica R. Elías ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Environmental Remediation ◽

Synthesis Method ◽

Mesoporous Structure ◽

Acid Orange 7 ◽

X Ray Diffraction ◽

Visible Radiation ◽

X Ray ◽

Transmission Electron ◽

Adsorption Desorption

Titanium dioxide materials were synthesized using two different methods. The samples were characterized by X-ray diffraction (XRD), UV–Visible diffusion reflectance spectroscopy (UV-Vis DR), Raman spectroscopy, N2 adsorption/desorption, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Although both kind of materials were found to have mesoporous structure and anatase crystalline phase, one of them was obtained from a synthesis method that does not involve the use of surfactants, and therefore, does not require calcination at high temperatures. This implies that the synthesized solid was self-doped with carbon species, coming only from the same source used for titanium. Then, the relationship between the presence of these species, the final calcination temperature, and the photocatalytic activity of the solids was studied in terms of the degradation and mineralization of an Acid Orange 7 aqueous solution, under visible radiation. A photosensitizing effect caused by the non-metal presence, that allows the solid to extend its absorption range, was found. Hence, a novel route to prepare C-modified photoactive mesoporous TiO2, simpler and cheaper, where neither a template nor an external carbon source is used, could be performed.

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Discussion the Mechanism of Sulfur and Phosphorus Doped TiO2

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.1157 ◽

2011 ◽

Vol 393-395 ◽

pp. 1157-1160

Author(s):

Tao Zeng ◽

Hou Juan Liu ◽

Zhan Shu

Keyword(s):

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Xenon Lamp ◽

X Ray Diffraction ◽

One Pot ◽

Preparation Methods ◽

X Ray ◽

Doping Mechanism ◽

Doped Titania ◽

Phosphorus Doped

Environmental pollution has become one of the most serious problems with the development of the world. TiO2 has caused great concern due to its excellent effort on the environmental puriﬁcation and solar energy conversion. N, S-doped titania were prepared by a one-pot hydrothermalmethod using urea and sulfourea as precursor of nitrogen and sulfur. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of them was evaluated for the degradation of methylene blue under xenon lamp which has similar spectra to solar light. The preparation methods and doping mechanism of the nitrogen-doped TiO2 are discussed. Morever, N, S-codoped titania can further enhacnce the photocatalytic activity effectively, This excellent performance could endow the as-prepared P-doped titania potential in purifying wastewater.

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Interfacial Synthesis of SiO2 Doped by Polyaniline and its Electrorheological Behavior

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.179-180.249 ◽

2011 ◽

Vol 179-180 ◽

pp. 249-252

Author(s):

Qing Ming Jia ◽

Shao Yun Shan ◽

Li Hong Jiang ◽

Ya Ming Wang

Keyword(s):

Silicone Oil ◽

Synthesis Method ◽

Tetraethyl Orthosilicate ◽

Molar Ratio ◽

X Ray Diffraction ◽

One Pot ◽

X Ray ◽

Sem Image ◽

Interfacial Synthesis ◽

Er Fluid

SiO2 doped by polyaniline for application in electrorheological (ER) ﬂuid was prepared by using a simple one-pot interfacial synthesis method. Scanning electron microscopy (SEM) image shows that the morphologies of SiO2 may be changed from spherical to fibroid structure by changing the molar ratio of tetraethyl orthosilicate(TEOS) and aniline. X-ray diffraction (XRD) proves that polyaniline does not change the crystallinity of SiO2. The ER behaviors of SiO2 doped by polyaniline in silicone oil are investigated with different doping degrees under different shear rate, and the results show that properly doping polyaniline improves electrorheological behavior of SiO2.

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One-Pot Hydrothermal Synthesis, Characterization, and Desulfurization Performance of ZnFe2O4/AC Composites

Journal of Nanotechnology ◽

10.1155/2018/9417067 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Hui-qiang Wang ◽

Ming-hua Liu ◽

Xin Luo ◽

Yi-fan Liu ◽

Fei-er Chen ◽

...

Keyword(s):

Adsorption Capacity ◽

Photoelectron Spectroscopy ◽

Performance Test ◽

X Ray Diffraction ◽

One Pot ◽

X Ray ◽

Synthesis Conditions ◽

Ft Ir ◽

The One ◽

Sulfur Adsorption

ZnFe2O4/AC composites were prepared by the one-pot hydrothermal method using the activated carbon (AC) as a carrier. The synthesis conditions were optimized by a single-factor experiment. The structural, textural, and surface properties of the adsorbent have been comprehensively characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, Brunauer–Emmett–Teller (BET) measurements, and X-ray photoelectron spectroscopy (XPS) analysis. The SO2 removal capacities of the composites were investigated via testing the adsorption capacity at the self-made desulfurization equipment. The results show that the adsorption capacity of ZnFe2O4/AC composites is much higher than that of the AC and ZnFe2O4 samples, respectively. The composite overcomes the disadvantages of the traditional sintering, showing a very high desulfurization performance. The breakthrough time was 147 min, and the sulfur adsorption capacity could reach 23.67% in the desulfurization performance test.

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