Effect of PVP on the morphology of cobalt nanoparticles prepared by thermal decomposition of cobalt acetate

2006 ◽  
Vol 6 ◽  
pp. e195-e197 ◽  
Author(s):  
Huiping Shao ◽  
Yuqiang Huang ◽  
HyoSook Lee ◽  
Yong Jae Suh ◽  
Chong Oh Kim
Keyword(s):  
Thermal Decomposition ◽  
Cobalt Acetate ◽  
Cobalt Nanoparticles

Preparation of Metallic Cobalt Nanoparticles by the Thermal Decomposition of CoC2O4. 2H2O Precursor in the Argon Gas

2011 ◽  
Vol 127 ◽  
pp. 85-88 ◽  
Author(s):  
Xiao Ming Fu
Keyword(s):  
Thermal Decomposition ◽  
Cobalt Nanoparticles ◽  
Cobalt Powder ◽  
Metallic Cobalt ◽  
Crystal Water ◽  
Argon Gas ◽  
Pyrolytic Decomposition ◽  
Two Stages

Metallic cobalt nanoparticles are successfully obtained by the pyrolytic decomposition of CoC2O4. 2H2O in the argon gas. The pyrolysates of CoC2O4. 2H2O were investigated by TG-DSC and SEM. The results showed that there are two stages in the process of the pyrolytic decomposition of CoC2O4. 2H2O in the argon gas. The crystal water in CoC2O4. 2H2O was lost from 150 °C to 275 °C. CoC2O4was pyrolysized into metallic cobalt powder from 300 °C to 500 °C. At the same time, the pattern of pyolysate of CoC2O4. 2H2O was fined at 347.7 °C for 10 min. But, the particles of pyolysate of CoC2O4. 2H2O were sintered into cobalt blocks at 500.0 °C for 10 min. Therefore, the conditions of pyrolytic decomposition of CoC2O4. 2H2O were controlled if single cobalt powder was obtained at 500.0 °C..

Size- and shape-controlled synthesis of monodisperse Co nanoparticles from cobalt acetate by thermal decomposition

Rare Metals ◽  
2009 ◽  
Vol 28 (3) ◽  
pp. 241-244 ◽  
Author(s):  
Tao Lin ◽  
Huiping Shao ◽  
Zhimeng Guo ◽  
Ji Luo ◽  
Junjie Hao
Keyword(s):  
Thermal Decomposition ◽  
Cobalt Acetate ◽  
Controlled Synthesis ◽  
Size And Shape ◽  
Shape Controlled ◽  
Co Nanoparticles

Synthesis and Characterization of Cobalt Nanoparticles by Cobalt-Acetate

2012 ◽  
Vol 503-504 ◽  
pp. 346-349
Author(s):  
Xia Yang ◽  
Hui Ping Shao
Keyword(s):  
Oleic Acid ◽  
Coercive Force ◽  
Cobalt Acetate ◽  
Cobalt Nanoparticles ◽  
Synthesis And Characterization ◽  
Hysteresis Curve ◽  
Vibrating Sample Magnetometer ◽  
Size Of Particles ◽  
Average Size

In this study, cobalt nanoparticles with an average size of 16 nm were synthesized using cobalt-acetate as precursor. Besides oleylamine and oleic acid, sodium oleate was selected as surfactants to control the size of particles. The obtained particles show cubic shape and uniformly disperse. The hysteresis curve of cubic nanoparticles detected by vibrating sample magnetometer (VSM) reveals that the coercive force Hc is 297.62 Oe and the saturation magnetization Ms is 56.55 emu/g.

Effect of surfactants on the size and shape of cobalt nanoparticles synthesized by thermal decomposition

2006 ◽  
Vol 99 (8) ◽  
pp. 08N702 ◽  
Author(s):  
Huiping Shao ◽  
Yuqiang Huang ◽  
HyoSook Lee ◽  
Yong Jae Suh ◽  
ChongOh Kim
Keyword(s):  
Thermal Decomposition ◽  
Cobalt Nanoparticles ◽  
Size And Shape

Cobalt nanoparticles synthesis from Co(CH3COO)2 by thermal decomposition

2006 ◽  
Vol 304 (1) ◽  
pp. e28-e30 ◽  
Author(s):  
Huiping Shao ◽  
Yuqiang Huang ◽  
HyoSook Lee ◽  
Yong Jae Suh ◽  
Chong Oh Kim
Keyword(s):  
Thermal Decomposition ◽  
Cobalt Nanoparticles ◽  
Nanoparticles Synthesis

scholarly journals In Situ-Formed Cobalt Nanoparticles Embedded Within Carbonaceous Matrix as Highly Efficient and Selective Catalysts for the Hydrogenation of Nitroarenes

2021 ◽  
Author(s):  
Xiuzheng Zhuang ◽  
Jianguo Liu ◽  
Shurong Zhong ◽  
Longlong Ma
Keyword(s):  
Metallic Nanoparticles ◽  
Catalytic Performance ◽  
Structural Features ◽  
Cobalt Acetate ◽  
Cobalt Nanoparticles ◽  
Aqueous System ◽  
Transfer Hydrogenation ◽  
Side Reactions ◽  
Electronic Interaction ◽  
One Pot

Inhibiting the side reactions (such as dehalogenation) while promoting both/transfer hydrogenation are the main target for the production of functional anilines from nitroarenes; consequently, the preparation of an ideal catalyst to improve reaction selectivity stays as the fundamental direction for this field. In this work, we provided an easy-to-prepared heterogeneous catalyst with multilayered graphene shells where cobalt nanoparticles were encapsulated inside and distributed uniformly. This as-prepared catalysts were fabricated via one-pot pyrolysis by using mixture of citrate acid and cobalt acetate as C source and Co source, respectively. First of all, structural features of catalyst were characterized by a series of analytic techniques involving XPS, SEM/EDS, TEM as well as elemental mapping, to reveal its unique properties in relation to the catalytic mechanisms; in simple terms, the outer graphitic shell could be activated by the electronic interaction between the inner metallic nanoparticles and the outer graphene layer. Subsequently, the catalytic performance was tested in hydrogenation of nitrobenezene by using H2 as hydrogen source, so as to optimize the preparation process as well as the reaction conditions. Other nitro aromatics with functional groups such as halogen atoms, methyl or hydroxyl were also tolerated under very mild industrially viable and scalable conditions (60 °C, 2 h, and 2 MPa H2). More surprisingly, this catalyst could still exhibit excellent yields over 96 % in gram-scale test for the selected substrates, and could also be easily separated from the aqueous system due to its magnetic properties. The determined yields of target products were not decreased even after eight cycles, suggesting a potential for future industrial application in the selective hydrogenation of nitroarenes to the corresponding amines.

scholarly journals Synthesis, Crystal Structure, and Thermal Decomposition of the Cobalt(II) Complex with 2-Picolinic Acid

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Di Li ◽  
Guo-Qing Zhong
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Picolinic Acid ◽  
Cobalt Acetate ◽  
Distorted Octahedral Geometry ◽  
Scanning Calorimetry ◽  
Monoclinic System ◽  
Cell Parameters ◽  
Composition And Structure ◽  
Final Residue

The cobalt(II) complex of 2-picolinic acid (Hpic), namely,[Co(pic)2(H2O)2]·2H2O, was synthesized with the reaction of cobalt acetate and 2-picolinic acid as the reactants by solid-solid reaction at room temperature. The composition and structure of the complex were characterized by elemental analysis, infrared spectroscopy, single crystal X-ray diffraction, and thermogravimetry-differential scanning calorimetry (TG-DSC). The crystal structure of the complex belongs to monoclinic system and space groupP2(1)/n, with cell parameters ofa=9.8468(7) Å,b=5.2013(4) Å,c=14.6041(15) Å,β=111.745(6)°,V=747.96(11) Å3,Z=2,Dc=1.666 g cm−3,R1=0.0297, andwR2=0.0831. In the title complex, the Co(II) ion is six-coordinated by two pyridine N atoms and two carboxyl O atoms from two 2-picolinic acid anions, and two O atoms from two H2O molecules, and forming a slightly distorted octahedral geometry. The thermal decomposition processes of the complex under nitrogen include dehydration and pyrolysis of the ligand, and the final residue is cobalt oxalate at about 450°C.

Synthesis of cobalt nanoparticles from [bis(2-hydroxyacetophenato)cobalt(II)] by thermal decomposition

Polyhedron ◽  
2009 ◽  
Vol 28 (6) ◽  
pp. 1065-1068 ◽  
Author(s):  
Masoud Salavati-Niasari ◽  
Zeinab Fereshteh ◽  
Fatemeh Davar
Keyword(s):  
Thermal Decomposition ◽  
Cobalt Nanoparticles

scholarly journals In Situ-Formed Cobalt Nanoparticles Embedded Within Carbonaceous Matrix as Highly Efficient and Selective Catalysts for the Hydrogenation of Nitroarenes

2021 ◽  
Author(s):  
Xiuzheng Zhuang ◽  
Jianguo Liu ◽  
Shurong Zhong ◽  
Longlong Ma
Keyword(s):  
Metallic Nanoparticles ◽  
Catalytic Performance ◽  
Structural Features ◽  
Cobalt Acetate ◽  
Cobalt Nanoparticles ◽  
Aqueous System ◽  
Transfer Hydrogenation ◽  
Side Reactions ◽  
Electronic Interaction ◽  
One Pot

Inhibiting the side reactions (such as dehalogenation) while promoting both/transfer hydrogenation are the main target for the production of functional anilines from nitroarenes; consequently, the preparation of an ideal catalyst to improve reaction selectivity stays as the fundamental direction for this field. In this work, we provided an easy-to-prepared heterogeneous catalyst with multilayered graphene shells where cobalt nanoparticles were encapsulated inside and distributed uniformly. This as-prepared catalysts were fabricated via one-pot pyrolysis by using mixture of citrate acid and cobalt acetate as C source and Co source, respectively. First of all, structural features of catalyst were characterized by a series of analytic techniques involving XPS, SEM/EDS, TEM as well as elemental mapping, to reveal its unique properties in relation to the catalytic mechanisms; in simple terms, the outer graphitic shell could be activated by the electronic interaction between the inner metallic nanoparticles and the outer graphene layer. Subsequently, the catalytic performance was tested in hydrogenation of nitrobenezene by using H2 as hydrogen source, so as to optimize the preparation process as well as the reaction conditions. Other nitro aromatics with functional groups such as halogen atoms, methyl or hydroxyl were also tolerated under very mild industrially viable and scalable conditions (60 °C, 2 h, and 2 MPa H2). More surprisingly, this catalyst could still exhibit excellent yields over 96 % in gram-scale test for the selected substrates, and could also be easily separated from the aqueous system due to its magnetic properties. The determined yields of target products were not decreased even after eight cycles, suggesting a potential for future industrial application in the selective hydrogenation of nitroarenes to the corresponding amines.

Sign in / Sign up

Export Citation Format

Share Document