Synthesis and Substitution Chemistry of Redox-Active Manganese/Cobalt Oxide Nanosheets
Synthesis and Substitution Chemistry of Redox-Active Manganese/Cobalt Oxide Nanosheets
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DOI：
10.1021/acs.chemmater.7b04068
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发表时间：
2018-02
影响因子：
8.6
通讯作者：
Nobuyuki Sakai;K. Fukuda;R. Ma;T. Sasaki
中科院分区：
文献类型：
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作者：
Nobuyuki Sakai;K. Fukuda;R. Ma;T. Sasaki
本文报道了Co取代的锰氧化物纳米片（Mn 1-xCoxO 2）的合成及其电化学性质。以Na_（0.6）Mn_（1-x）Co_xO_2（x = 0.2-0.5）为原料，合成了层状多晶样品。随着Co含量的增加，晶格常数a线性减小，这支持了Co 3+离子对Mn 3+离子在宿主层中的成功替代。Na0.6Mn1-xCoxO 2粉末的酸交换处理导致H-Mn 1-xCoxO 2的形成，同时保持Mn/Co比和层状结构。通过与四正丁基铵离子反应实现H-Mn 1-xCoxO 2的剥离，得到厚度为0.8 nm的单层Mn 1-xCoxO 2（x = 0.2-0.5）纳米片。随着Co含量的增加，Mn 1-xCoxO 2纳米片的光吸收峰不断蓝移。Mn 1-xCoxO 2纳米片具有明确的氧化还原峰，随着Co含量的增加，氧化还原峰向负电位移动。这些结果表明Mn和Co的3d轨道是混合的。
We report the synthesis and electrochemical properties of Co-substituted manganese oxide nanosheets (Mn1–xCoxO2). Polycrystalline samples of layered Na0.6Mn1–xCoxO2 (x = 0.2–0.5) were synthesized as starting materials. A linear decrease in the lattice constant a with increasing Co content supported the successful substitution of Co3+ ions for Mn3+ ions in the host layers. Acid-exchange treatment of the Na0.6Mn1–xCoxO2 powders resulted in the formation of H–Mn1–xCoxO2 while preserving the Mn/Co ratio and layered structure. Exfoliation of H–Mn1–xCoxO2 was achieved by reaction with tetra–n–butylammonium ions, yielding unilamellar Mn1–xCoxO2 (x = 0.2–0.5) nanosheets with a thickness of 0.8 nm. The optical absorption peak of the obtained Mn1–xCoxO2 nanosheets was continuously blueshifted as the Co content increased. The Mn1–xCoxO2 nanosheets exhibited well-defined redox peaks, which were shifted to a negative potential with increasing Co content. These results suggest that the 3d orbitals of Mn and Co are mixe...