- Reaction of octacarbonyldicobalt with the free radicals galvinoxyl and 2,2-diphenyl-1-picrylhydrazyl. Attempts to scavenge the tetracarbonylcobalt radical
-
The addition of galvinoxyl or 2,2-diphenyl-1-picrylhydrazyl to octacarbonyldicobalt in n-octane solution results in the loss of all carbon monoxide ligands and the formation of Co(II)-containing products.
- Tuba, Róbert,Ungváry, Ferenc
-
-
Read Online
- Facile synthesis of Co3O4 with different morphology and their application in supercapacitors
-
In this article, direct growth of Co3O4 with different morphologies on nickel foam is successfully achieved via a simple hydrothermal method by changing the volume ratio between ethanol and water. The morphology and structure of the as-prepared samples are examined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The electrochemical performance of the Co3O4 electrodes is investigated as pseudocapacitor material by cyclic voltammetry and galvanostatic charge/discharge test in 3 mol L-1 KOH solution. Results show that the solvent composition plays an important role not only in the morphology but also in the capacitance. Co3O4 with a honeycomb structure obtained from the volume ratio of C2H5OH/H2O = 1 exhibits the highest capacitive performance, 2509.4 F g-1 at 1 A g-1 and 1754 F g-1 at 10 A g-1, which is much larger than that prepared in the pure water and pure ethanol solvent. The electrode also has a satisfactory cycling performance with capacity retention of 74% after 1000 cycles at 10 A g-1. The enhanced electrochemical performance is ascribed to the honeycomb nanostructure allowing facile electrolyte flow which speeds up electrochemical reaction kinetics. These findings may open up the opportunity for optimizing the hydrothermal synthesis conditions to control the morphology and performance of the products.
- Ouyang, Tian,Cheng, Kui,Kong, Shuying,Ye, Ke,Gao, Yinyi,Zhang, Dingfu,Wang, Guiling,Cao, Dianxue
-
-
Read Online
- Thermal analysis of cobalt(II) salts with Some carboxylic acids
-
The thermal analysis of CoC2O4·2H2O, Co(HCOO)2·2H2O and Co(CH3COO)2·H2O was carried out with simultaneous TG-DTG-DTA measurements under non-isothermal conditions in air and argon atmospheres. The intermediates and the end products of decomposition were characterised by X-ray diffraction and IR and UV-VIS spectroscopy. The decomposition of the studied compounds occur in several stages. The first stage of dissociation of each compound is dehydration both in air and argon. The next stages differ in air and argon. The final product of the decomposition of each compound in air is Co3O4. In argon it is a mixture of Co and CoO for cobalt(II) oxalate and cobalt(II) formate but CoO for cobalt(II) acetate.
- Ingier-Stocka,Grabowska
-
p. 115 - 123
(2008/10/08)
-
- ELECTROCHEMICAL SYNTHESIS OF COBALT ACETATE.
-
Investigational results are presented relative to the direct production of cobalt acetate from metallic cobalt in an electrochemical systems of the form: electrode-electrolyte 1-ion-exchange membrane-electrolyte 2-electrode, with application of direct current. The results indicate the possibility of obtaining cobalt acetate with the optimal current efficiency for electrochemical systems by application of direct current. The potential gradient at the membrane separating the cathode and anode compartments was determined.
- Konnova,Ryazanov
-
p. 393 - 395
(2008/10/08)
-