A fast route to obtain manganese spinel nanoparticles by reduction of K-birnessite

作者：Giovannelli F^*; Chartier T; Autret Lambert C; Delorme F; Zaghrioui M; Seron A

来源：Journal of Solid State Chemistry, 2009, 182(5): 1021-1026.

DOI：10.1016/j.jssc.2009.01.031

• Nanoparticles
• Birnessite
• Hausmanite
• Reduction
• Spinel

The K-birnessite (K(x)MnO(2)center dot yH(2)O) reduction reaction has been tested in order to obtain manganese spinel nanoparticles. The addition of 0.25 weight percent of hydrazine hydrate, the reducing agent, during 24 hours is efficient to transform the birnessite powder in a hausmanite Mn(3)O(4) powder. Well crystallised square shape nanoparticles are obtained. Different birnessite precursors have been tested and the reaction kinetics is strongly correlated to the crystallinity and granulometry of the precursor. The effects of aging time and hydrazine hydrate amount have been studied. Well crystallised Mn(3)O(4) is obtained in one hour. The presence of feitknechtite (MnO(OH)) and amorphous nanorods has been detected as all intermediate phase during birnessite conversion into hausmanite. The conversion mechanism is discussed.

• 出版日期2009-5
• 单位中国地震局