I change the pH of the solution using NaOH, the process is hydrothermal synthesis, and the final particle size increase while the pH is more basic. thanks
Vanadium(V) oxide react with oxalic acid to produce vanadium(IV) oxide, carbon dioxide and water. Oxalic acid - diluted solution.
V2O5 + H2C2O4 → 2VO2 + 2CO2 + H2O
When you add the lye in the process is hydrothermal synthesis formed vanadates
V2O5 +6NaOH = 2Na3VO4 + 3H2O
and the final particle size increase.
Best regards.
Vanadium(V) oxide react with oxalic acid to produce vanadium(IV) oxide, carbon dioxide and water. Oxalic acid - diluted solution.
V2O5 + H2C2O4 → 2VO2 + 2CO2 + H2O
When you add the lye in the process is hydrothermal synthesis formed vanadates
V2O5 +6NaOH = 2Na3VO4 + 3H2O
and the final particle size increase.
Best regards.
At low pH , small particle size , good homogeneity and low agglomeration is expected. At high pH , the homogeneity of particles became poorer , more agglomeration and a growth in the particle size(crystallites are aggregate into large particles) may be observed .
The chemical species are change from HVO3 to Na3VO4 as the pH of solution changes from acidic to basic and different V2O5 morphologies are resulting under hydrothermal treatment
Dear Diana,
first of all, the answer by Yuri Mirgorod is surely the most complete, as concerns your specific question.
More generally, there is a good example about the influence of pH on the crystallization product: the CaCO3 polymorphs. From the same carbonatic solution one can precipitate, at constant temperature, either vaterite, or aragonite and calcite, according to the solution pH. This proves the importance of the pH on the supersaturation and not only on the nucleation frequency, which, in turn, influences the crystal size.
All the best
Dino
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