Speciation of iron;: characterisation and structure of green rusts and FeII-III oxyhydroxycarbonate fougerite
Speciation of iron;: characterisation and structure of green rusts and FeII-III oxyhydroxycarbonate fougerite
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DOI：
10.1016/j.crte.2006.04.005
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发表时间：
2006-06-01
影响因子：
1.4
通讯作者：
Upadhyay, Chandan
中科院分区：
文献类型：
--
作者：
Genin, Jean-Marie R.;Abdelmoula, Mustapha;Upadhyay, Chandan
Fe-II-Fe-III，羟基盐绿锈（GR）是一种反应性很强的层状双氢氧化物，主要通过XRD和穆斯堡尔光谱进行表征。本文综述了主要化合物的穆斯堡尔谱，重点介绍了由一个或两个亚铁重态和一个铁重态组成的GRs谱。通过XRD谱图证实，GR的结构为fei - ii (OH)(6)八面体和阴离子层交替的水镁石状层叠加序列。存在绿锈1 （GR1）和绿锈2 （GR2）两种结构，分别有R(3)在barm和P(3)在bar上m1空间群。铁层内和层间的正离子和阴离子分布与穆斯堡尔谱成分的丰度相匹配。综上所述，fougerite矿物为部分去质子化的fei - iii型羟基碳酸盐，分子式为Fe-6(l-x)(II) (Fe6xO12H2(7-3x)CO3)-O-III，其中x在[(1/3),(2/3)]范围内。Mg-II和Al-III的阳离子取代不能排除将辉石与其他矿物如辉石和水滑石联系起来。
Fe-II-Fe-III, hydroxysalt green rusts (GR) are very reactive layered double hydroxides that can be characterised mainly by XRD and Mossbauer spectroscopy. Mossbauer spectra of the main compounds presented in this article are reviewed with special emphasis on those of GRs constituted of one or two ferrous doublets and one ferric doublet. The structure of GR has a stacking sequence of alternating brucite-like layers of FeII-II(OH)(6) octahedrons and anion interlayers as confirmed from XRD patterns. There exist two kinds of structure named green rust one (GR1) and green rust two (GR2) with R (3) over barm and P (3) over bar m1 space groups, respectively. Cation and anion distributions within Fe layers and interlayers match abundances of Mossbauer spectrum components. In the view of that, it can be suggested that the fougerite mineral is partially deprotonated FeII-III, hydroxycarbonate with a general formula Fe-6(l-x)(II) (Fe6xO12H2(7-3x)CO3)-O-III, where x is within the range [(1/3), (2/3)]. Cation substitution by Mg-II and Al-III cannot be excluded relating fougerite with other minerals like pyroaurite and hydrotalcite.