Formation and conversion mechanisms between single-crystal gamma-MnOOH and manganese oxides
- Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong 518055 (China)
- Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)
Highlights: ► Single-crystal γ-MnOOH was obtained via hydrothermal method. ► α-MnO{sub 2} was transformed to γ-MnOOH by a dissolution-growth-recrystallization process. ► α-MnO{sub 2} preferred growth on (111{sup ¯}) crystal plane of γ-MnOOH. ► γ-MnOOH was a useful precursor to prepare manganese oxide via calcination. -- Abstract: Formation and conversion mechanisms between single-crystal gamma-MnOOH and manganese oxides had investigated systematically. Without extra surfactant or template, α-MnO{sub 2} nanorods and prismatic single crystalline γ-MnOOH rods had been synthesized under hydrothermal treatment in this study. The formation and conversion mechanisms of prismatic γ-MnOOH rod were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It was found that the formation process includes three evolution stages: (1) formation of α-MnO{sub 2} nanorods whiskers; (2) transformation from α-MnO{sub 2} nanorods to prismatic γ-MnOOH rods by a dissolution-growth-recrystallization process; and (3) preferred growth on (111{sup ¯}) crystal plane. In addition, β-MnO{sub 2}, Mn{sub 2}O{sub 3} or Mn{sub 3}O{sub 4} rods could be obtained by calcination of the γ-MnOOH rods at different temperatures, which indicated that γ-MnOOH is an important precursor for preparing manganese oxides. The morphology and dimension of γ-MnOOH rods remained unchanged after converted to β-MnO{sub 2}, Mn{sub 2}O{sub 3} and Mn{sub 3}O{sub 4}.
- OSTI ID:
- 22215147
- Journal Information:
- Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 7 Vol. 47; ISSN MRBUAC; ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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