Microwave-Assisted Synthesis of Ag Nanophases and Their Optical Properties

2010 ◽  
Vol 10 (12) ◽  
pp. 8035-8042 ◽  
Author(s):  
Dongsheng Li ◽  
Sridhar Komarneni
Keyword(s):  
Optical Properties ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

Size-Controlled Microwave-Assisted Synthesis of Water-Dispersible Cd(Se,S) Quantum Dots for Potential Biological Applications

2015 ◽  
Vol 1784 ◽  
Author(s):  
E. Calderón-Ortiz ◽  
S. Bailón-Ruiz ◽  
L. Alamo-Nole ◽  
J. Rodriguez-Orengo ◽  
O. Perales-Perez
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Quantum Confinement Effect ◽  
Reactive Oxygen Species Generation ◽  
Size Control ◽  
Average Crystallite Size ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

ABSTRACTNanomedicine is fostering significant advances in the development of platforms for early detection and treatment of diseases. Nanoparticles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in bio-imaging, sensing and photo-dynamic therapy (PDT) applications. The present research addresses the synthesis of water-stable Cd-based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- and S-precursors, respectively. Selenide ions were available by reductive leaching of metallic Selenium in Sodium bisulfite solution. The size control and the tunability of the optical properties were achieved by a suitable control of the reaction temperature (in the 140°C- 190°C range) and reaction time (10 minutes-40 minutes). X-ray diffraction analyses suggested the development of a CdSe,S face cubic centered structure; the broadening of the diffraction peaks indicated the presence of very small nanocrystals in the samples. The average crystallite size was estimated at 5.50 nm ± 1.17nm and 3.72 nm ± 0.04 nm, for nanoparticles synthesized at 180°C after 40 minutes or 10 minutes of reaction, respectively. HRTEM images confirmed the crystalline nature and the small size of the synthesized nanocrystals. In turn, the exciton was red-shifted from 461nm to 549 nm when the reaction temperature was prolonged from 140°C to 190 °C, suggesting the crystal growth. The corresponding band gap values were approximately 2.2 eV, confirming the quantum confinement effect (bulk value 1.74eV). This red shift was also evidenced in PL measurements where the main emission peak was shifted from 507 nm to 564 nm when the samples were excited at 420 nm. A narrow size-tunable emission also was supported by the full width at half maximum (∼ 45 nm) for the synthesized nanocrystals. The reactive oxygen species generation capability of as-synthesized QDs was also investigated. The correlation between the particle size and the generation of (ROS) by the degradation of methylene blue was evident with a reduction of MB concentration from 10μM to 7.5μM and 6.7μM after 15 minutes of UV irradiation for reaction time of 10 min. and 40 min. respectively. No additional degradation was noticed after 60 minutes of irradiation.

Structural and optical properties of ZnO nanopowder prepared by microwave-assisted synthesis

2010 ◽  
Vol 130 (10) ◽  
pp. 1756-1759 ◽  
Author(s):  
Y.C. Lee ◽  
C.S. Yang ◽  
H.J. Huang ◽  
S.Y. Hu ◽  
J.W. Lee ◽  
...  
Keyword(s):  
Optical Properties ◽  
Microwave Assisted Synthesis ◽  
Structural And Optical Properties ◽  
Microwave Assisted ◽  
Zno Nanopowder

scholarly journals Ultrafast ammonia-driven, microwave-assisted synthesis of nitrogen-doped graphene quantum dots and their optical properties

Nanophotonics ◽  
2017 ◽  
Vol 6 (1) ◽  
pp. 259-267 ◽  
Author(s):  
Binjie Zheng ◽  
Yuanfu Chen ◽  
Pingjian Li ◽  
Zegao Wang ◽  
Bingqiang Cao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Graphene Quantum Dots ◽  
Microwave Assisted Synthesis ◽  
Scale Production ◽  
Excitation Spectra ◽  
Nitrogen Doped ◽  
Microwave Assisted ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

AbstractFor the first time, a facile, ultrafast, ammonia-driven microwave-assisted synthesis of high-quality nitrogen-doped graphene quantum dots (NGQDs) at room temperature and atmospheric pressure is presented. This one-step method is very cheap, environment friendly, and suitable for large-scale production. The as-synthesized NGQDs consisting of one to three graphene monolayers exhibit highly crystalline quality with an average size of 5.3 nm. A new fluorescence (FL) emission peak at 390 nm is observed, which might be attributed to the doped nitrogen atoms into the GQDs. An interesting red-shift is observed by comparing the FL excitation spectra to the UV-visible absorption spectra. Based on the optical properties, the detailed Jablonski diagram representing the energy level structure of NGQDs is derived.

scholarly journals MICROWAVE-ASSISTED SYNTHESIS AND OPTICAL PROPERTIES OF HYPERBRANCHED POLYIMIDES CONTAINING TRIPHENYLPYRIDINE STRUCTURE

2010 ◽  
Vol 00 (11) ◽  
pp. 1313-1319
Author(s):  
Wenqiu CHEN ◽  
Chuan CHEN ◽  
Shanyin YAN ◽  
Xiaojin YANG ◽  
Changfeng YI ◽  
...  
Keyword(s):  
Optical Properties ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Hyperbranched Polyimides

Microwave-assisted synthesis and optical properties of cuprous oxide micro/nanocrystals

2014 ◽  
Vol 60 ◽  
pp. 704-708 ◽  
Author(s):  
Dandan Sun ◽  
Yi Du ◽  
Xiuying Tian ◽  
Zhongfu Li ◽  
Zhongtao Chen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cuprous Oxide ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

ZnS nanosheets: Egg albumin and microwave-assisted synthesis and optical properties

2016 ◽  
Vol 59 ◽  
pp. 39-43 ◽  
Author(s):  
Xiuying Tian ◽  
Jin Wen ◽  
Jilin Hu ◽  
Zhanjun Chen ◽  
Shumei Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Microwave Assisted Synthesis ◽  
Egg Albumin ◽  
Microwave Assisted ◽  
Zns Nanosheets
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