Shape-controlled Synthesis of Silver and Palladium Nanocrystals using β-Cyclodextrin

2012 ◽  
Vol 1446 ◽  
Author(s):  
Gilles Berhault ◽  
Hafedh Kochkar ◽  
Abdelhamid Ghorbel
Keyword(s):  
Ascorbic Acid ◽  
Strong Influence ◽  
Sodium Citrate ◽  
Catalytic Properties ◽  
Relative Concentration ◽  
Reducing Agent ◽  
Molar Ratio ◽  
Controlled Synthesis ◽  
Primary Particles ◽  
Shape Controlled

ABSTRACTShape-controlled Ag and Pd nanocrystals were synthesized using seed-mediated techniques using β-cyclodextrin (β-CD) as structuring agent. First, seeds were obtained by reacting Na2PdCl4 or AgNO3 with a strong reducing agent, NaBH4 in the presence of sodium citrate dihydrate acting as stabilizing agent. These seeds were then injected into a growth solution containing the same metallic precursor, ascorbic acid (as a weak reducing agent) and β-CD as structuring agent. TEM results emphasize a strong influence of the relative concentration of β-CD on the final morphology. In the case of silver, well-facetted nanocrystals were obtained with a progressive shift from kinetically to thermodynamically-controlled nanoobjects when increasing the β-CD/Ag molar ratio. On palladium, β-CD leads to the formation of dendrites (urchin-like) or multipods through controlled aggregation of primary particles. The use of β-CD does not interfere negatively with the catalytic properties of the Pd nanocrystals in the hydrogenation of cinnamaldehyde.

Shape-controlled synthesis of palladium nanocrystals by microwave irradiation

2009 ◽  
Vol 81 (12) ◽  
pp. 2377-2385 ◽  
Author(s):  
Yanchun Yu ◽  
Yanxi Zhao ◽  
Tao Huang ◽  
Hanfan Liu
Keyword(s):  
Microwave Irradiation ◽  
Microwave Heating ◽  
Reducing Agent ◽  
Tetraethylene Glycol ◽  
Controlled Synthesis ◽  
Shape Controlled

The controlled synthesis of Pd icosahedra in tetraethylene glycol (TEG) with H2PdCl4 as a precursor and poly(vinylpyrrolidone) (PVP) as a stabilizer in the presence of an appropriate amount of KOH under microwave irradiation was demonstrated. TEG served as both solvent and reducing agent, and stable Pd icosahedra with uniform sizes and well-defined shapes could be prepared in a yield of over 90 % by microwave heating for 60 s. The sizes of Pd icosahedra can be well controlled by adjusting the concentration of the precursor H2PdCl4.

Shape-controlled synthesis of CO-free Pd nanocrystals with the use of formic acid as a reducing agent

2016 ◽  
Vol 52 (85) ◽  
pp. 12594-12597 ◽  
Author(s):  
Shixiong Bao ◽  
Xuan Yang ◽  
Ming Luo ◽  
Shan Zhou ◽  
Xue Wang ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Formic Acid ◽  
Reducing Agent ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Controlled Synthesis ◽  
Ft Ir ◽  
Shape Controlled ◽  
No Chemisorption ◽  
Ft Ir Spectroscopy

This paper reports the use of formic acid as a reducing agent for the shape-controlled synthesis of Pd nanocrystals with no chemisorption of CO on the surface, as confirmed by attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy.

Shape-controlled synthesis of 3D copper nicotinate hollow microstructures and their catalytic properties

RSC Advances ◽  
2016 ◽  
Vol 6 (22) ◽  
pp. 18033-18039 ◽  
Author(s):  
Shanshan Fu ◽  
Qingdong Xia ◽  
Shuang Li ◽  
Guojuan Ren ◽  
Fang Chai ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Controlled Synthesis ◽  
Shape Controlled ◽  
Hollow Microstructures

View of the process of preparation and catalysis of Cu hollow microstructures.

Shape-controlled synthesis for silver: Triangular/hexagonal nanoplates, chain-like nanoplate assemblies, and nanobelts

2009 ◽  
Vol 24 (7) ◽  
pp. 2200-2209 ◽  
Author(s):  
Xin He ◽  
Xiujian Zhao ◽  
Yuanzhi Li ◽  
Xiaotao Sui
Keyword(s):  
Strong Interaction ◽  
Secondary Growth ◽  
Experimental Results ◽  
Vinyl Pyrrolidone ◽  
Molar Ratio ◽  
Process Time ◽  
Controlled Synthesis ◽  
Shape Controlled ◽  
Poly Vinyl Pyrrolidone ◽  
Hexagonal Nanoplates

Individual triangular/hexagonal nanoplates, chain-like nanoplate assemblies, and nanobelts in the case of silver were selectively synthesized using N,N-dimethylformamide (DMF) in the presence of poly (vinyl pyrrolidone) (PVP). The molar ratio of AgNO3/PVP, concentration of AgNO3, temperature, and process time were crucial factors in determining the morphologies of the final products. Based on the experimental results, it was concluded that the products were favorable to form individual nanoplates because of the strong interaction between PVP and Ag+, and the outline of the nanoplates was controlled by the ratio of AgNO3 and PVP. The formation of novel chain-like nanoplate assemblies could be explained by the secondary growth of the nanocrystals. If the reaction continuously lasted for another 7 h, the chain-like assemblies could transform into nanobelts with width of 40∼100 nm and the length of several micrometers.

scholarly journals Formation of Molybdenum Blue Nanoparticles in the Organic Reducing Area

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4438
Author(s):  
Maria Myachina ◽  
Natalia Gavrilova ◽  
Victor Nazarov
Keyword(s):  
Ascorbic Acid ◽  
Molybdenum Oxide ◽  
Rate Constant ◽  
Maximum Concentration ◽  
Particle Formation ◽  
Reducing Agent ◽  
Molar Ratio ◽  
Dispersed Phase ◽  
Molybdenum Blue ◽  
Stable Dispersion

Molybdenum blue dispersions were synthesized by reducing an acidic molybdate solution with glucose, hydroquinone and ascorbic acid. The influence of the H/Mo molar ratio on the rate of formation of molybdenum particles was established. For each reducing agent, were determined the rate constant and the order of the particle formation and were established the conditions for the formation of aggregative stable dispersion with the maximum concentration of particles. The dispersed phase is represented by toroidal molybdenum oxide nanoclusters, which was confirmed by the results of UV/Vis, FTIR, XPS spectroscopy and DLS.

Shape-controlled synthesis of Mn2O3hollow structures and their catalytic properties

CrystEngComm ◽  
2015 ◽  
Vol 17 (38) ◽  
pp. 7406-7413 ◽  
Author(s):  
Ruiting Dong ◽  
Honglei Wang ◽  
Quan Zhang ◽  
Xuetang Xu ◽  
Fan Wang ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Controlled Synthesis ◽  
Shape Controlled

Shape-Controlled Synthesis of Copper Nanocrystals in an Aqueous Solution with Glucose as a Reducing Agent and Hexadecylamine as a Capping Agent

2011 ◽  
Vol 123 (45) ◽  
pp. 10748-10752 ◽  
Author(s):  
Mingshang Jin ◽  
Guannan He ◽  
Hui Zhang ◽  
Jie Zeng ◽  
Zhaoxiong Xie ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Reducing Agent ◽  
Controlled Synthesis ◽  
Capping Agent ◽  
Shape Controlled

SHAPE-CONTROLLED SYNTHESIS OF RUTHENIUM NANOPARTICLES

2011 ◽  
Vol 04 (04) ◽  
pp. 337-340
Author(s):  
MING YU ◽  
XIANGJU DIAO ◽  
TAO HUANG ◽  
HANFAN LIU ◽  
JINLIN LI
Keyword(s):  
Molecular Weight ◽  
Absorption Spectroscopy ◽  
Average Molecular Weight ◽  
Triethylene Glycol ◽  
Average Diameter ◽  
Reducing Agent ◽  
Controlled Synthesis ◽  
Ruthenium Nanoparticles ◽  
Ru Nanoparticles ◽  
Shape Controlled

Uniform pompon-like Ru nanoparticles with an average diameter of 148 nm were readily synthesized by reducing RuCl 3 with triethylene glycol (TG) as both a reducing agent and a solvent in the presence of PVP by oil-bath heating at 170°C for 6 h. The as-prepared Ru nano-pompons were characterized by TEM, XRD, XPS and UV-vis absorption spectroscopy. The effects of some parameters such as the average molecular weight and the concentration of PVP on the synthesis of Ru nano-pompons were investigated.

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