Room‐Temperature Direct Synthesis of Tetragonal β‐CsPbI 3 Nanocrystals

2021 ◽  
pp. 2101869
Author(s):  
Dejian Chen ◽  
Decai Huang ◽  
Mingwei Yang ◽  
Kunyuan Xu ◽  
Jie Hu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Direct Synthesis

scholarly journals Room Temperature Syntheses of ZnO and Their Structures

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 733
Author(s):  
Domenica Donia ◽  
Elvira Maria Bauer ◽  
Mauro Missori ◽  
Ludovica Roselli ◽  
Daniele Cecchetti ◽  
...  
Keyword(s):  
Room Temperature ◽  
Direct Synthesis ◽  
Threshold Value ◽  
Rietveld Analysis ◽  
Synthesis Temperature ◽  
Density Variation ◽  
Controlled Synthesis ◽  
Sem Images ◽  
Aqueous Solvent ◽  
Average Size

ZnO has many technological applications which largely depend on its properties, which can be tuned by controlled synthesis. Ideally, the most convenient ZnO synthesis is carried out at room temperature in an aqueous solvent. However, the correct temperature values are often loosely defined. In the current paper, we performed the synthesis of ZnO in an aqueous solvent by varying the reaction and drying temperatures by 10 °C steps, and we monitored the synthesis products primarily by XRD). We found out that a simple direct synthesis of ZnO, without additional surfactant, pumping, or freezing, required both a reaction (TP) and a drying (TD) temperature of 40 °C. Higher temperatures also afforded ZnO, but lowering any of the TP or TD below the threshold value resulted either in the achievement of Zn(OH)2 or a mixture of Zn(OH)2/ZnO. A more detailed Rietveld analysis of the ZnO samples revealed a density variation of about 4% (5.44 to 5.68 gcm−3) with the synthesis temperature, and an increase of the nanoparticles’ average size, which was also verified by SEM images. The average size of the ZnO synthesized at TP = TD = 40 °C was 42 nm, as estimated by XRD, and 53 ± 10 nm, as estimated by SEM. For higher synthesis temperatures, they vary between 76 nm and 71 nm (XRD estimate) or 65 ± 12 nm and 69 ± 11 nm (SEM estimate) for TP =50 °C, TD = 40 °C, or TP = TD = 60 °C, respectively. At TP = TD = 30 °C, micrometric structures aggregated in foils are obtained, which segregate nanoparticles of ZnO if TD is raised to 40 °C. The optical properties of ZnO obtained by UV-Vis reflectance spectroscopy indicate a red shift of the band gap by ~0.1 eV.

Facile and direct synthesis of symmetrical acid anhydrides using a newly prepared powerful and efficient mixed reagent

2015 ◽  
Vol 69 (3) ◽  
Author(s):  
Hamed Rouhi-Saadabad ◽  
Batool Akhlaghinia
Keyword(s):  
Carboxylic Acids ◽  
Room Temperature ◽  
Low Cost ◽  
Direct Synthesis ◽  
Reaction Conditions ◽  
Experimental Procedure ◽  
Short Reaction Time ◽  
Acid Anhydrides ◽  
Work Up ◽  
Trichloroisocyanuric Acid

AbstractAn efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.

In situ organogelation at room temperature: direct synthesis of gelators in organic solvents

2004 ◽  
Vol 2 (8) ◽  
pp. 1155 ◽  
Author(s):  
Masahiro Suzuki ◽  
Yasushi Nakajima ◽  
Mariko Yumoto ◽  
Mutsumi Kimura ◽  
Hirofusa Shirai ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Room Temperature ◽  
Direct Synthesis

scholarly journals Laser-Induced Photochemical Reaction of Maleic Acid Solutions in the Presence of Hydrogen Peroxide

1997 ◽  
Vol 17 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Yuichi Shimizu ◽  
Shun'ichi Sugimoto ◽  
Shunichi Kawanishi ◽  
Nobutake Suzuki
Keyword(s):  
Hydrogen Peroxide ◽  
Maleic Acid ◽  
Photochemical Reaction ◽  
Room Temperature ◽  
Direct Synthesis ◽  
Reaction Scheme ◽  
Photochemical Reactions ◽  
The Other ◽  
Acid Solutions ◽  
Selective Formation

Targeting the selective and direct synthesis of tartaric acid (TA), the photochemical reactions of maleic acid (MA) solutions containing H2O2. in various solvents have been investigated using four wavelengths in the UV region between 193 and 351 nm, with high intensity from an excimer laser. All the laser irradiations in H2O resulted in the direct synthesis of TA with lower selectivity and it was found that, with XeF-laser (351 nm) irradiation in 1,4-dioxane, TA is selectively and directly synthesized from MA containing H2O2 of lower concentration at room temperature. On the other hand, none of the irradiations in methanol, N,N-dimethylformamide, acetonitrile, and tetrahydrofuran gave the selective formation of TA. On the basis of these results, the reaction scheme for the selective formation of TA is discussed.

Electrical resistivity and photoluminescence of lead iodide crystals

2007 ◽  
Vol 61 (1) ◽  
Author(s):  
M. Matuchová ◽  
K. Žďánský ◽  
M. Svatuška ◽  
J. Zavadil ◽  
O. Procházková
Keyword(s):  
Electrical Resistivity ◽  
Optical Properties ◽  
Room Temperature ◽  
Direct Synthesis ◽  
Zone Melting ◽  
Lead Iodide ◽  
Electrical And Optical Properties ◽  
X Ray ◽  
Low Temperature Photoluminescence

AbstractDirect synthesis of lead iodide, a promising material for X-ray and γ detectors operating at room temperature, was developed and optimized. The influence of admixture of rare earth elements Ce, Ho, Gd, Yb, Er, and Tb in concentrations 0.05–0.5 at. % on the quality of prepared PbI2 was investigated. Zone melting was employed in order to increase the lead iodide purity. Electrical and optical properties of PbI2 samples were assessed on the basis of the measurement of electrical resistivity and low-temperature photoluminescence. The electrical resistivity of synthesized samples varied from 109 Ω cm to 1011 Ω cm and occasionally it was increased up to 1013 Ω cm.

scholarly journals Direct synthesis of ultrafine tetragonal BaTiO3 nanoparticles at room temperature

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Jian Quan Qi ◽  
Tao Peng ◽  
Yong Ming Hu ◽  
Li Sun ◽  
Yu Wang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Direct Synthesis ◽  
Batio3 Nanoparticles
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