MICROWAVE HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF Co3O4 NANOCRYSTALS

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2841-2846 ◽  
Author(s):  
GUOBIN MA ◽  
SHUNHUA ZHOU ◽  
SHISONG HUANG
Keyword(s):  
Aqueous Solution ◽  
Hydrothermal Synthesis ◽  
Hold Time ◽  
Synthesis And Characterization ◽  
High Quality ◽  
Hold Temperature ◽  
Microwave Hydrothermal ◽  
Microwave Hydrothermal Method ◽  
Incomplete Reaction

Microwave hydrothermal method is employed to synthesize Co 3 O 4 nanocrystals. Co ( OH )2 from reaction of C 4 H 6 CoO 4·4 H 2 O with NaOH aqueous solution is used as starting material. With a fixed hold time of an hour, the results show that high quality Co 3 O 4 nanocrystals can be synthesized at 200 °C. Decrease of the hold temperature leads to deteriorated crystallinity and incomplete reaction.

Co-Containing LDHs Synthesized by the Microwave-Hydrothermal Method

2006 ◽  
Vol 514-516 ◽  
pp. 1241-1245
Author(s):  
Patricia Benito ◽  
Maria Herrero ◽  
Francisco Martin Labajos ◽  
Vicente Rives
Keyword(s):  
Oxidation State ◽  
Layered Double Hydroxides ◽  
Treatment Time ◽  
Synthesis And Characterization ◽  
Thermal Treatments ◽  
Microwave Hydrothermal ◽  
Microwave Hydrothermal Method ◽  
Divalent Cobalt ◽  
Double Hydroxides

The synthesis and characterization of Co,Al Layered Double Hydroxides (LDHs) containing carbonate is reported. The solids have been submitted to several thermal treatments, hydrothermal and microwave-hydrothermal, modifying both the treatment time and temperature, with the main aim of studying their influence on the crystallinity of the solids and on the stabilization of divalent cobalt oxidation state. The results show that whichever the temperature and time used the only phase detected was the hydrotalcite, and that the cobalt cations keep the divalent oxidation state.

Microwave-hydrothermal synthesis and characterization of Co-VSB-5 microporous framework

2007 ◽  
Vol 15 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Bharat L. Newalkar ◽  
T. Chiranjeevi ◽  
N. V. Choudary ◽  
S. Komarneni
Keyword(s):  
Hydrothermal Synthesis ◽  
Synthesis And Characterization ◽  
Microwave Hydrothermal

Hydrothermal Synthesis of Vanadium Oxides

1996 ◽  
Vol 453 ◽  
Author(s):  
Thomas Chirayil ◽  
Peter Zavalij ◽  
M. Stanley Whittingham
Keyword(s):  
Acetic Acid ◽  
Hydrothermal Synthesis ◽  
Critical Factor ◽  
Vanadium Oxides ◽  
Synthesis And Characterization ◽  
Cluster Compound ◽  
Soft Chemistry ◽  
Microwave Hydrothermal ◽  
Reaction Media

AbstractThe pH of the reaction media is a critical factor in the formation of new vanadium oxides with the tetramethylammonium (TMA) ion via the conventional hydrothermal method. New vanadium oxides; TMAV3O7, Li0.6V2−δO4−δ·H2O and Li0.6V2−δO4−δ, TMAV4O10, and two more new vanadium phases with d spacings of 11.5Å and 19.1Å are formed as the pH is varied with acetic acid. The synthesis and characterization of TMAV3O7, a new vanadium oxide with tetramethylammonium ions residing between its layers is discussed. The intercalation of alkylamines, DMSO, and water into Li0.6V2−δO4−δ·H2O is described. Microwave hydrothermal synthesis is a new and alternate soft chemistry technique used to accelerate the synthesis of TMAV4O10. This method also aided in the formation of a new cluster compound, [Li(H2O)4]2TMA(V10O28)·4H2O.

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