中文摘要：

以水热合成方法制备了具有不同微观形貌的纳米结构MnO2,并以X射线衍射（XRD）,扫描电镜（SEM）和X射线光电子能谱（XPS）等方法对其进行了表征.跟踪考察了二氧化锰的晶型及微观形貌随水热反应时间的演变过程,在Ostwald ripening机理作用下,MnO2晶型转化过程为γ-MnO2,α-MnO2和β-MnO2,同时形貌由微米球转变为海胆结构、空心海胆结构和纳米线.

英文摘要：

Manganese dioxides with various morphologies were prepared with a common hydrothermal method without any templates or additives. The morphological evolution was accompanied with the conversion of the polymorphic forms, gradually from T-type to β-type. Meanwhile, MnO2 microspheres, urchinlike nanostructures and nanowires were successfully synthesized. The products were characterizeal via X-ray powder diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope. The process can be explained with Ostwald-Ripening mechanism.