Effects of pH on the Todorokite Formation from Cu-Buserite at Atmospheric Pressure
Todorokite is a common manganese oxide with tunnel structure on the Earth surface and was mainly synthesized through Na-buserite (Na-buserite exchanged with different metal ions as an interlayer ion) as the precursor. The effects of pH on the formation of Cu-buserite and transformation to todorokite during refluxing process at atmospheric pressure were studied in this paper. However, todorokite formation rate was proportional to the amount of Cu2+ in the solution, and Na-buserite converted completely to todorokite over 4 mmol of Cu2+ when the pH of the solution was adjusted to 4. 5. The difference between the above two transformations of Na-buserite to todorokite was correlative to the change of sub-structure of Na-buserite at different pH and the form of Cu2+ in the interlayer of Cu-buserite.