Synthesis and electrochemical properties of nanophase MnO2 by solid-phase reaction(I) - Synthesis and characterization of nanophase gamma-MnO2

Manganese acetate was complexed with citric acid, oxalic acid and 8-hydroxy quinoline respectively in solid state. The resulted complex precursors were thermally decomposited and then treated with acid to obtain nanophase gamm a-MnO2. Their physical properties were characterized and discussed by eleme ntary analysis, XRD, chemical analysis, TEM and TG/DTA tests. The particle sizes of samples are about 20-30 nm and their shapes are spherical-like fro m TEM images. The acid treatment made the oxidition of mangnese dioxide inc rease but nanophase samples have a little of agglomeration, the process of the acid treatment seemed to be crystalization, and the particles may be di rectional growth. The reason that nanophase materials could be systhesized with solid state reactions under the condition of room temperature or low h eating was discussed.