Compositional variations in anodic nanotubes/nanopores formed on Fe 100, 110 and 111 single crystals
Compositional variations in anodic nanotubes/nanopores formed on Fe 100, 110 and 111 single crystals
复制标题
DOI：
10.1016/j.electacta.2020.137316
复制
发表时间：
2020-12
影响因子：
6.6
通讯作者：
L. Fadillah;D. Kowalski;Y. Aoki;H. Habazaki
中科院分区：
文献类型：
--
作者：
L. Fadillah;D. Kowalski;Y. Aoki;H. Habazaki
铁（100）、（110）和（111）单晶在含有1.5 mol dm-3水和0.1 mol dm-3氟化铵的单乙二醇电解质中的阳极化导致阳极铁纳米孔/纳米管的形成，其中纳米孔基本上由被氟化铁基质隔开的氧化物纳米管组成。结果发现，纳米多孔/纳米管膜形成的电化学热力学显然取决于其上形成的阳极膜的刻面的指数。在（100）面上的膜形成与阳极氧化时延长的气体析出相关联，并且因此对应于电流-时间曲线与在更高指数面上形成的那些相比向更高电流密度值的偏移。在（100）面上形成的纳米管具有化学通式Fe 2 O3·FeF 2，而在更高指数上形成的纳米管由Fe 3 O 4·FeF 2组成。在Fe（110）和Fe（111）面上形成的阳极膜基本上是无定形的，而在（100）面上形成的阳极膜显示出高度的结晶性。根据铁的各向异性性质对结果进行了讨论。
Anodizing of iron (100), (110) and (111) single crystals in mono-ethylene-glycol electrolyte containing 1.5 mol dm−3water and 0.1 mol dm−3ammonium fluoride leads to formation of anodic iron nanopores/nanotubes where the nanopores are essentially composed of oxide nanotubes separated by iron fluoride matrix. It was found that electrochemical thermodynamics for nanoporous/nanotubular film formation apparently depends on the index number of facet on which the anodic film is formed. The film formation on (100) facet is associated with extended gas evolution upon anodizing and consequently corresponds to a shift of current-time curve towards higher current density values comparing with those formed on higher index number facets. The nanotubes formed on (100) facet have a general chemical formula of Fe2O3.FeF2, whereas those formed on higher index number are composed of Fe3O4.FeF2. The anodic films formed on Fe (110) and Fe (111) are essentially amorphous whereas the one formed on (100) facet shows high degree of crystallinity. The results are discussed in view of anisotropic properties of iron.