US EPA

7826199 

Journal Article 

Synthesis of birnessite-type sodium manganese oxides by solution reaction and hydrothermal methods 

Feng, Q; Sun, EH; Yanagisawa, K; Yamasaki, N 

1997 

Yes 

Ceramic Society of Japan. Journal
ISSN: 1882-0743 

105 

7 

564-568 

10.2109/jcersj.105.564 

WOS:A1997XM93900004 

A birnessite-type sodium manganese oxide with a layered structure was synthesized by the reaction of Mn(NO3)2 solution with a mixed solution of H2O2 and NaOH at room temperature. This sodium manganese oxide was hydrothermally treated in neutral, acidic and alkaline solutions at 150°C. The original samples which were synthesized at room temperature and hydrothermally treated samples were characterized by XRD, DTA-TG, FT-IR spectroscopy and chemical analysis. The formation of the birnessite-type sodium manganese oxide is dependent on the mixed mole ratio of NaOH/Mn(NO3)2. The fraction of the birnessite phase increased with increase in mixed mole ratio of NaOH/Mn(NO3)2. The birnessite-type manganese oxide has a basal spacing of 1.004nm before air-drying, but it changes to 0.724nm after the air-drying at room temperature. A well crystallized birnessite phase with a basal spacing of 0.724nm was obtained by hydrothermally treating the birnessite-type sodium manganese oxide prepared at room temperature with a NaOH solution. 

synthesis; sodium manganese oxide; layered structure; birnessite; hydrothermal treatment