Laboratoire de Technologie des Matériaux et Génie des Procédés (LTMGP), Département de Génie des Procédés, Université A. Mira, Route de Targa Ouzemmour, Béjaia, Algeria.
ACS Appl Mater Interfaces. 2009 Feb;1(2):424-32. doi: 10.1021/am800118y.
The influence of synthesizing temperature of manganese dioxide (MnO(2)) powders on their electrochemical reactivity in 1 M KOH was investigated. These powders were prepared chemically by the hydrothermal method by oxidation of Mn(2+) by ammonium peroxodisulphate. The observations by scanning electronic microscopy, energy-dispersive X-ray analyses, and transmission electron microscopy techniques on MnO(2) obtained at different temperatures show the formation of many nanometre scale sticks lumped together to form a spherical particle of several micrometers. The results obtained by BET and BJH methods reveal mesoporous texture, and the MnO(2) synthesized at 90 degrees C presents the largest expanded surface area. The electrochemical reactivity of these powders in 1 M KOH was characterized with microcavity electrode by cyclic voltammetry and electrochemical impedance spectroscopy. The results illustrate that the nanostructured MnO(2) powder synthesized at 90 degrees C shows the highest electrochemical reactivity in agreement with BET data. The X-ray powder diffraction identified the gamma-MnO(2), known as the most reactive species.
研究了二氧化锰（MnO(2)）粉末的合成温度对其在 1 M KOH 中的电化学反应性的影响。这些粉末是通过水热法通过过硫酸铵氧化 Mn(2+)化学合成的。在不同温度下获得的 MnO(2)的扫描电子显微镜、能谱分析和透射电子显微镜观察表明，形成了许多纳米级别的棒状物质，聚集在一起形成了几个微米的球形颗粒。BET 和 BJH 方法得到的结果表明其具有介孔结构，在 90°C 下合成的 MnO(2)具有最大的扩展表面积。通过微腔电极的循环伏安法和电化学阻抗谱对这些粉末在 1 M KOH 中的电化学反应性进行了表征。结果表明，与 BET 数据一致，在 90°C 下合成的纳米结构 MnO(2)粉末具有最高的电化学活性。X 射线粉末衍射确定了最具反应性的 γ-MnO(2)。
