Synthesis of Prismatic Single Crystal γ-MnOOH

Prismatic single crystalγ-MnOOH was synthesized by a hydrothermal method through oxidizing Mn(CH_3COO)_2 with HMnO_4 at 150℃.The advantage of oxidizing agent HMnO_4 is that no other metallic ions coming into the product structures.The synthesized samples were characterized by XRD,SEM,TEM,HRTEM and TG.It is found that the formation process of single crystalγ-MnOOH includes two primary evolution stages:(1)theγ-MnOOH whiskers are initially formed,and(2)the whiskers grow to prismatic single crystalγ-MnOOH by an adsorption-growth process,(11(?))plane grows faster than other planes,because the surface energy of each crystal plane is different,the different growth rate makes the whiskers changed to prismatic crystal.The hydrothermal reaction time is the major factor that influences crystal morphology.TG results show that the single crystalγ-MnOOH is transferred to MnO_2 at 350℃.