Abstract Single-crystalline α-MnO 2 nanorods have been successfully prepared via in situ hydrothermal decomposition of single KMnO 4 under different acidic conditions. The as-synthesized products were characterized with X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), selected area electron diffraction (SAED), high-resolution transmission electron microscope (HRTEM), and Fourier transformation infrared spectroscopy (FT-IR). The effects of various experimental conditions on the phase structures and morphology of the final products were investigated. Formation mechanism for the MnO 2 nanorods was discussed on the basis of the experimental results. The results show that the usage and kinds of acids used in the experiments can influence the phase of the final products considerably. Phase-pure α-MnO 2 nanorods can be obtained in a wide temperature range from 100 to 150 °C. Electrochemical studies of the MnO 2 materials prepared at 150 °C for different hydrothermal times indicate that the MnO 2 materials prepared for 5 and 8 h show fine capacitive behaviors and high specific capacitances of 83.9 and 79.3 F/g, respectively.

中文翻译：

---

α-MnO2纳米棒的简便合成及其电化学性能

摘要 通过在不同酸性条件下对单个KMnO 4 进行原位水热分解，成功制备了单晶α-MnO 2 纳米棒。合成产物通过 X 射线粉末衍射 (XRD)、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、选区电子衍射 (SAED)、高分辨透射电子显微镜 (HRTEM) 和傅里叶变换红外光谱 (FT-IR)。研究了各种实验条件对最终产物的相结构和形貌的影响。在实验结果的基础上讨论了MnO 2 纳米棒的形成机制。结果表明，实验中使用的酸的用量和种类会显着影响最终产品的相。相纯的α-MnO 2 纳米棒可以在100至150°C的宽温度范围内获得。对在 150 °C 下制备的 MnO 2 材料进行不同水热时间的电化学研究表明，制备 5 小时和 8 小时的 MnO 2 材料显示出良好的电容行为和分别为 83.9 和 79.3 F/g 的高比电容。