scholarly journals Taming Polysulfides in an Li–S Battery With Low-Temperature One-step Chemical Synthesis of Titanium Carbide Nanoparticles From Waste PTFE

2021 ◽  
Vol 9 ◽  
Author(s):  
Suyao Liu ◽  
Jun Luo ◽  
Yuting Xiong ◽  
Zhe Chen ◽  
Kailong Zhang ◽  
...  

In this work, titanium carbide (TiC) nanoparticles have been successfully synthesized at much lower temperatures of 500°C using cheaper starting materials, such as waste polytetrafluoroethylene (PTFE) (carbon source) and titanium and metallic sodium, than the traditional carbothermal reduction of TiO2 at 1,800°C. An XRD pattern proved the formation of face-centered cubic TiC, and TEM images showed the obtained TiC nanoparticles with an average size of approximately 50 nm. In addition, the separator coated with TiC nanoparticles as an active material of interlayer effectively mitigates the shuttling problem by taming the polysulfides in Li–S batteries compared with a traditional celgard separator. The assembled cell realizes good cycling stability with 501 mAh g−1 and a low capacity fading of 0.1% per cycle after 300 cycles at 1 C due to high utilization of the sulfur-based active species.

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
M. Z. Kassaee ◽  
F. Buazar ◽  
E. Motamedi

Arc-fabricated copper nanoparticles (Cu Nps) size, morphology and the crystalline structure, as well as the yields of Nps appear sensitive to the applied currents (50–160 A) in distilled water. The results indicate that the sizes of Cu Nps are directly proportional to the currents employed. At 50 A, TEM, XRD, and SEM analyses show fabrication of relatively purest, the most dispersed, face-centered cubic (fcc) brown Cu Nps with rather smallest average size of 20 nm. At the same current, the TGA-DTA analysis reveals neither weight loss nor gain, indicating thermal stability of the fabricated Cu Nps.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1777 ◽  
Author(s):  
Md. Mahiuddin ◽  
Prianka Saha ◽  
Bungo Ochiai

A green synthesis of silver nanoparticles (AgNPs) was conducted using the stem extract of Piper chaba, which is a plant abundantly growing in South and Southeast Asia. The synthesis was carried out at different reaction conditions, i.e., reaction temperature, concentrations of the extract and silver nitrate, reaction time, and pH. The synthesized AgNPs were characterized by visual observation, ultraviolet–visible (UV-vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The characterization results revealed that AgNPs were uniformly dispersed and exhibited a moderate size distribution. They were mostly spherical crystals with face-centered cubic structures and an average size of 19 nm. The FTIR spectroscopy and DLS analysis indicated that the phytochemicals capping the surface of AgNPs stabilize the dispersion through anionic repulsion. The synthesized AgNPs effectively catalyzed the reduction of 4-nitrophenol (4-NP) and degradation of methylene blue (MB) in the presence of sodium borohydride.


2013 ◽  
Vol 712-715 ◽  
pp. 233-236
Author(s):  
Hui Ping Shao ◽  
Zhi Wang ◽  
Tao Lin ◽  
Sen Sun

CoPt nanoparticles with an average size of 2.8 – 4.7 nm were synthesized by reduction of non-toxic precursors Co(CH3COO)2and Pt(acac)2using trioctylamine as a solvent at reaction temperature of 260 – 280 °C. The X-ray diffraction pattern showed that as-prepared particles have a disordered face-centered cubic structure while annealing at 700 °C caused them to be an ordered face-centered tetragonal structure. The annealing increased magnetic coercivity of the particles from zero to 772.4 Oe and their saturated magnetization from 15.04 to 27.95 emu/g.


Author(s):  
Hend Ezzat Salama ◽  
Mohamed Samir Abdel Aziz

Background:: Novel eco-friendly silver nanocomposites of xanthan/chitosan biguanidine hydrochloride polyelectrolyte complexes were successfully prepared. Methods:: Silver nanoparticles (AgNPs) were formed through an insitu eco-friendly reduction by the non-toxic polysaccharides without the usage of toxic reagents. FTIR confirmed the successful preparation of the nanocomposites while XRD confirmed the presence of AgNPs with face-centered cubic structures. TEM confirmed the homogeneous distribution of AgNPs with an average size of 14.1 nm. SEM was used to study the surface morphology of the nanocomposites while the energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of AgNPs. Results:: Thermogravimetric analysis showed that the thermal stability was improved in the presence of AgNPs as detected from the calculated integral procedure decomposition temperature. Antibacterial activity against different bacteria species was significantly improved upon increasing the content of AgNPs. Conclusion:: Due to their interesting properties, the prepared polyelectrolyte complexes and their AgNPs nanocomposites could be employed potentially in many biomedical applications like drug delivery.


2020 ◽  
Vol 20 (3) ◽  
pp. 1678-1684
Author(s):  
Jiraporn Chumpol ◽  
Sineenat Siri

Green synthesis offers an eco-friendly and low-cost approach for the synthesis of silver nanoparticles (AgNPs). Many studies have reported on the use of biomolecules, especially plant extracts, as reducing and/or stabilizing agents in place of toxic chemicals. This study reports on the use of bacterial genomic DNA as an alternative stabilizing agent for the green synthesis of AgNPs under light activation. With both increased DNA quantities and reaction times under light exposure, more stabilized AgNPs formed as indicated by the surface plasmon resonance intensities. The synthesized AgNPs were spherical with an average size of 61.36±10.15 nm as calculated using the dynamic light scattering (DLS) technique. The X-ray diffraction, selected area electron diffraction, and high resolution transmission electron microscope (TEM) analyses confirmed the formation of face-centered cubic (fcc) structured AgNPs. The produced AgNPs exhibited antibacterial activities against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, suggesting its potential application as an antibacterial agent.


2010 ◽  
Vol 25 (4) ◽  
pp. 711-717 ◽  
Author(s):  
Wei-Qiang Han ◽  
Dong Su ◽  
Michael Murphy ◽  
Matthew Ward ◽  
Tsun-Kong Sham ◽  
...  

PtPd@Pt core-shell ultrathin nanowires were prepared using a one-step phase-transfer approach. The diameters of the nanowires range from 2 to 3 nm, and their lengths are up to hundreds of nanometers. Line scanning electron energy loss spectra showed that PtPd bimetallic nanowires have a core-shell structure, with a PtPd alloy core and a Pt monolayer shell. X-ray absorption near edge structure (XANES) spectra reveal that a strong Pt-Pd interaction exists in this nanowire system in that there is PtPd alloying and/or interfacial interaction. Extended x-ray absorption fine structures (EXAFS) further confirms the PtPd@Pt core-shell structure. The bimetallic nanowires were determined to be face-centered cubic structures. The long-chain organic molecules of n-dodecyl trimethylammonium bromide and octadecylamine, used as surfactants during synthesis, were clearly observed using aberration-corrected TEM operated at 80 KV. The interaction of Pt and surfactants was also revealed by EXAFS.


1991 ◽  
Vol 6 (4) ◽  
pp. 755-759 ◽  
Author(s):  
R. Allem ◽  
G. L'Espérance ◽  
Z. Altounian ◽  
J.O. Ström-Olsen

The microstructure of two metastable crystalline phases, which are formed during the first step of the crystallization process in Ni–Zr metallic glasses, was investigated by transmission electron microscopy. For the composition Ni33Zr67, crystallites with average size of 150 nm having the face-centered cubic E93 structure are formed. For the Ni42Zr58 composition, 100 nm size crystallites with a simple cubic unit cell, space group Pa3 are formed. The microstructure of the crystallites in the early stage of crystallization of the two phases is similar to globular morphology and internal striations.


2020 ◽  
Vol 9 (1) ◽  
pp. 503-514 ◽  
Author(s):  
Khaleeq Uz-Zaman ◽  
Jehan Bakht ◽  
Bates Kudaibergenova Malikovna ◽  
Eman R. Elsharkawy ◽  
Anees Ahmed Khalil ◽  
...  

AbstractSynthesis of nanoparticles is a fast-growing area of interest in the current development in science and technology. Nanoparticles are also used in biomedical applications. Green synthesis of nanoparticles is an environmental friendly and cost-effective technique. Trillium govanianum Wall. Ex. Royle crude extract was used for the eco-friendly genesis of silver nanoparticles (AgNPs). Aromatic amines were the functional groups involved in the bio-fabrication and synthesis of the AgNPs. The production of AgNPs was established by the appearance of brown color. The manufactured AgNPs were characterized by UV-Vis spectrophotometer, X-ray diffractometer, and FTIR spectrophotometer. AgNPs were face-centered cubic in nature with an average size of 9.99 nm. The produced AgNPs (18 µL disc−1) showed substantial antibacterial (53.74, 52.75, 51.61, 43.00, 36.84, and 36.84%) and antifungal (54.05, 42.11, 41.10, 40.85, 30.55, and 29.73%) potential against the tested bacterial (X. campestris, P. aeruginosa, S. aureus, E. coli, B. subtilis, and K. pneumoniae) and fungal (A. alternaria, Paecilomyces, C. albicans, Curvularia, A. niger, and Rhizopus) strains, respectively.


2020 ◽  
Vol 21 (4) ◽  
pp. 177
Author(s):  
Siti Suhartati ◽  
Iwan Syahjoko Saputra ◽  
Dwinna Rahmi ◽  
Yoki Yulizar ◽  
Sudirman Sudirman

BIOREDUCTION AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM OIL PALM EMPTY FRUIT BUNCH (OPEFB). The synthesis of silver nanoparticles was successfully carried out by extracting oil palm empty fruit bunch. The precursor used was silver nitrate (AgNO3) with a concentration of 9x10-4 M and 5 wt% of the oil palm empty fruit bunch extract. OPEFB acted as a capping agent in the synthesis of silver nanoparticles. The bioreduction method Ag+ to Ag0 produced a silver nanoparticle colloid in brown color. The results of the UV-Vis spectrophotometer showed the silver nanoparticles colloids spectrum at a wavelength of 420 nm with an absorbance value of 0.5. FTIR shows the reduction and shift of absorption peak in the hydroxyl functional group (-OH) at wavenumbers of 3323 cm-1 and the presence of absorption peaks at 560 cm-1. While, XRD pattern showed the specific crystallinity peaks of silver nanoparticles at 2θ: 33.24°; 39.98°; 61.23°; dan 79.13° respectively with the face-centered cubic crystal structure (FCC) and crystallite size of 15 nm. PSA analysis showed two specific peaks with an average size distribution silver nanoparticles of 43.5 nm and a PDI value of 0.4. Analysis of TEM shows the average particle size of 20 nm with a spherical particle shape.


2005 ◽  
Vol 879 ◽  
Author(s):  
Chunwei Wu ◽  
Brian P. Mosher ◽  
Taofang Zeng

AbstractIn this paper, we describe a simple and rapid solution-phase chemical reduction method with no inert gas protection, for preparing stable copper nanoparticle colloid with average particle size of 3.4 nm and narrow size distribution. In our synthesis route, ascorbic acid, natural vitamin C (VC), serves as both a reducing agent and an antioxidant to reduce copper salt precursor and effectively prevent the general oxidation process occurring to the newborn nanoparticles. XRD and UV/vis confirm the formation of pure face-centered cubic (fcc) copper nanoparticles and the excellent antioxidant ability of ascorbic acid.


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