The 2D Rancieite-type manganic acid and its alkali-exchanged derivatives: Part I — Chemical characterization and thermal behavior

The 2D Rancieite type manganic acid was prepared by reduction of KMnO₄ in acidic medium. Its ion exchange behavior allows to prepare alkali derivatives. All compounds were characterized with use of a combination of X-ray diffraction, chemical analyses, TGA, magnetic measurements and spectroscopic techniques. The evolution of their chemical composition versus temperature was studied between 180 and 400 °C. It shows that the dehydration process is partly reversible in these compounds whereas the weak reduction is irreversible. The 2D Rancieite-type manganic acid is readily different from a Birnessite-type phyllomanganate, as shown by several features: the interlayer distance, the ion exchange capacity, the thermal behavior, the interlayer cation content, the manganese average oxidation state, the magnetic behavior and the IR spectrum.     

Charge manipulation and imaging of the Mn acceptor state in GaAs by cross-sectional scanning tunneling microscopy

An individual Mn acceptor in GaAs is mapped by cross-sectional scanning tunneling microscopy (X-STM) at room temperature and a strongly anisotropic shape of the acceptor state is observed. An acceptor state manifests itself as a cross-like feature which we attribute to a valence hole weakly bound to the Mn ion forming the (Mn²⁺3d⁵+hole) complex. We propose that the observed anisotropy of the Mn acceptor wavefunction is due to the d-wave present in the acceptor ground state.     

荧光猝灭法测定人发中微量锰

异丙肾上腺素在pH9.91的伯瑞坦 罗比森缓冲溶液中被MnO-4氧化,导致其荧光强度显著减弱。最大激发及发射波长为278nm和616nm,MnO-4浓度在0.01～0.64mg·L-1范围内,荧光强度与浓度呈良好线性关系。将其用于人发中微量锰的测定,得到满意的结果。     

过氧化物模拟酶在介体型生物传感器方面应用初探

meso-四(4-磺基苯)卟啉锰(Ⅲ)作为过氧化物模拟酶可催化H_2O_2与K_4Fe(CN)_6反应。电流响应与H_2O_2浓度在3.0×10~(-4)～1.0×10~(-3)mol/L范围内呈线性关系。重现性和回收率良好。抗坏血酸和DL-半胱氨酸干扰严重。     

草酸锰分解过程的机理函数判别和动力学研究

用等温热重和线性升温热重分析法研究了草酸锰热分解过程,提出了判断其机理函数的3步判别法。经实验和理论分析证明,该反应受随机成核和晶核随后生长的过程(A_3a机理)支配,其活化能E=103.95 kJ/mol,频率因子A=4.448×10~8min~(-1).动力学补偿效应为IgA=0.09661E-1.2856     

Effect of BaBiO3 and Ba0.6K0.4BiO3 additives on the rechargeability of manganese oxide cathodes in alkaline cells

The effect of the incorporation of small amounts (1–5 wt%) of semiconducting BaBiO₃ and metallic Ba_0.6K_0.4BiO₃ additives on the rechargeability of electrolytic manganese dioxide (EMD) cathodes in alkaline cells in the one-electron regime has been investigated. Both the BaBiO₃ and Ba_0.6K_0.4BiO₃ additives lead to better cyclability compared to the previously known binary oxide additive Bi₂O₃. X-ray diffraction patterns recorded before and after 30 cycles as well as cyclic voltammograms recorded after first and 30 cycles reveal that the better cyclability in the presence of BaBiO₃ and Ba_0.6K_0.4BiO₃ additives is due to the suppression of the formation of unwanted, electrochemically inactive birnessite and hausmannite phases and a shifting of the second-electron capacity of Mn to higher potentials.     

锰的催化光度法测定现状与展望

介绍催化光度法测定锰的分析方法，讨论各显色体系中的灵敏度、测定范围和干扰情况，比较了测定锰的显色剂。引用文献58篇。     

酞菁锰-表面活性剂薄膜电极的电化学表征及其对三氯乙酸的电化学催化作用的研究

将酞菁锰（ＭｎＰｃ）掺入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）的氯仿溶液，并涂布于热解石墨电极表面，待氯仿挥发后即制得ＭｎＰｃ－ＤＤＡＢ薄膜电极。循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有两对还原氧化峰，第一对峰的Ｅｐｃ１＝－０．２７Ｖ，Ｅｐａ１＝０．０１Ｖ；第二对峰的Ｅｐｃ２＝－０．７６Ｖ，Ｅｐａ２＝－０．６２Ｖ（ｖｓ．ＳＣＥ）。本文着重探讨了第二对峰的电化学行为，估计了该体系的电荷传递扩散系数Ｄｃｔ和表观非均相电极反应速率常数Ｋ０′等电化学参数，并可将该薄膜电极用于催化三氯乙酸的电化学还原。     

互通多孔碳/二氧化锰纳米复合材料的原位水热合成及电化学性能

以互通多孔碳（IPC）为载体，水热条件下在碳表面原位反应生成纳米结构的二氧化锰（MnO₂），制备互通多孔碳/二氧化锰纳米（IPC/MnO₂）复合电极材料. 采用扫描电镜（SEM），透射电镜（TEM），X射线衍射（XRD），热重分析（TGA）对其结构进行表征；采用循环伏安法、恒流充放电和交流阻抗对其电化学性能进行研究. 结果表明：生成的MnO₂均匀地负载在碳的表面，形成多层次结构，并且随着温度的升高IPC表面负载的MnO₂由纳米颗粒变为纳米片状结构；MnO₂纳米片具有典型的K-Birnessite 型晶体结构；复合物中MnO₂的含量约为34%（w）. 在100 ℃制备的IPC/MnO₂复合材料在三电极系统中最高比电容达到了411 F·g^-1；随着反应温度的升高,比容量先增长后基本保持不变. 以IPC/MnO₂为正极，活性炭（AC）为负极，1 mol·L^-1 Na₂SO₄溶液为电解液组装成IPC/MnO₂//AC 混合超级电容器，发现IPC/MnO₂电极的电容器其电位窗口从1 V扩展到1.8 V，容量可达86F·g^-1，且表现出良好的电容特性和大电流放电性能.