Atomistic simulation of the surface structure of electrolytic manganese dioxide
Atomistic simulation of the surface structure of electrolytic manganese dioxide
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DOI：
10.1016/j.susc.2009.07.038
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发表时间：
2009-11-01
期刊：
影响因子：
1.9
通讯作者：
Ngoepe, P. E.
中科院分区：
文献类型：
--
作者：
Maphanga, R. R.;Parker, S. C.;Ngoepe, P. E.
采用原子模拟方法研究了电解二氧化锰（EMD）软锰矿和斜方锰矿多晶型的表面结构和稳定性。使用固体的玻恩模型描述了原子之间的相互作用。该模型用于计算软锰矿和斜方锰矿的低折射率表面{0 0 1}、{0 1 0}、{0 1 1}、{1 0 0}、{1 0 1}和{1 1 0}的结构和能量。软锰矿与金红石是同构的，并且与金红石相似，发现{1 1 0}表面最稳定，松弛表面能为2.07 J m(-2)。相比之下，斜方锰矿的{1 0 1}表面最稳定，表面能为1.52 J m(-2)。软锰矿{1 0 0}和斜方锰矿{1 0 0}(b)表面分别具有2.43 J m(-2)和2.45 J m(-2)的等效能量和相似的表面积，因此是共生体的可能来源。最后，还原能的比较表明，软锰矿的表面越稳定，就越容易被还原。 (C) 2009 Elsevier B.V. 保留所有权利。
Atomistic simulation methods were used to investigate the surface structures and stability of pyrolusite and ramsdellite polymorphs of electrolytic manganese dioxide (EMD). The interactions between the atoms were described using the Born model of Solids. This model was used to calculate the structures and energies of the low index surfaces {0 0 1}, {0 1 0}, {0 1 1}, {1 0 0}, {1 0 1} and {1 1 0} for both pyrolusite and ramsdellite. Pyrolusite is isostructural with rutile and similar to rutile the {1 1 0} surface is found to be the most stable with the relaxed surface energy 2.07 J m(-2). In contrast, for ramsdellite the {1 0 1} surface is the most stable with a surface energy of 1.52 J m(-2). Pyrolusite {1 0 0} and ramsdellite {1 0 0}(b) surfaces have equivalent energies of 2.43 J m(-2) and 2.45 J m(-2), respectively and similar surface areas and hence are the likely source for the intergrowths. Finally, comparison of the energies of reduction suggests that the more stable surfaces of pyrolusite are more easily reduced. (C) 2009 Elsevier B.V. All rights reserved.