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Single phase and well-crystallined todorokite were synthesized by heating and re-fluxing process from birnessite as a precursor. The average chemical composition of the synthe-sized todorokites by refluxing for 8 h and for 24 h was Mg0.19MnO2.11(H2O)1.15 and Mg0.17- MnO2.10(H2O)0.88, respectively. The crystallinity of the todorokite increased and no other phase was produced with increasing refluxing period. The synthesized todorokites have the same morphologies and the similar structural characteristics with the natural todorokites and hydro-thermally synthesized samples. The chemical compositions of the synthetic tordorokites by re-fluxing process are close to those of todorokites synthesized by hydrothermal process, except a higher average oxidation state of Mn for the former.
Single phase and well-crystallized todorokite were synthesized by heating and re-fluxing process from birnessite as a precursor. The average chemical composition of the synthe-sized todorokites by refluxing for 8 h and for 24 h was Mg0.19 MnO2.11 (H2O) 1.15 and Mg0.17- MnO2.10 (H2O) 0.88, respectively. The crystallinity of the todorokite increased and no other phase was produced with increasing refluxing period. The synthesized todorokites have the same morphologies and the similar structural characteristics with the natural todorokites and hydro-thermally synthesized samples. The chemical compositions of the synthetic tordorokites by re-fluxing process are close to those of todorokites synthesized by hydrothermal process, except a higher average oxidation state of Mn for the former.