Coprecipitation of Fe(II-III) hydroxycarbonate green rust stabilised by phosphate adsorption
Coprecipitation of Fe(II-III) hydroxycarbonate green rust stabilised by phosphate adsorption
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DOI：
10.1016/j.solidstatesciences.2003.10.004
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发表时间：
2004-01-01
影响因子：
3.5
通讯作者：
Génin, JMR
中科院分区：
文献类型：
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作者：
Bocher, F;Géhin, A;Génin, JMR
[(Fe4Fe2III)-Fe-II(OH)(12)](2+) .[CO3, nH(2)O](2-) 绿锈菌 GR1(CO32-) 在磷酸盐存在下溶解 Na2HPO4 盐，通过共沉淀法合成。如果不存在，所得产物是 Fe(II-III) 羟基盐、磁铁矿 Fe3O4 和氢氧化亚铁 Fe(OH)(2) 的混合物。在磷酸盐含量低至 {[PO4](0)(min)/[Fe])（接近 1%）的情况下，所得产物仅为 GR1(CO32-)。当分析基底（0001）晶面时，TEM-EDX 没有检测到 P，这表明 GR 中没有插入 P。相比之下，当对 GR 晶体的侧面进行分析时，检测到的 P 含量非常低。通过 ICP-AES 对溶液中的 P 进行分析，评估磷酸盐吸附物质的数量。代表沉淀物及其表面的模型表明，吸附的磷酸盐的数量与侧面存在的 Fe 原子的数量具有相同的数量级。磷酸盐物质优先用于侧面是因为{10 (1) 优于 bar0} 面包含单配位和双配位 OH- 表面基团。吸附在侧面的 PO43- 可以充当屏障，减缓 CO32- 物质在溶液中的释放，防止 GR1(CO32-) 转化为 Fe3O4 和 Fe(OH)(2) 的混合物。 (C) 2003 爱思唯尔 SAS。版权所有。
[(Fe4Fe2III)-Fe-II(OH)(12)](2+) .[CO3, nH(2)O](2-) green rust one, GR1(CO32-), was synthesised by coprecipitation in the presence of phosphate by dissolving a Na2HPO4 salt. In its absence, the resulting product is a mixture of Fe(II-III) hydroxysalt, magnetite Fe3O4 and ferrous hydroxide Fe(OH)(2). In the presence of phosphate as low as {[PO4](0)(min)/[Fe]) similar to 1%, the resulting product is GR1(CO32-) alone. No P was detected by TEM-EDX when the basal (0001) crystal faces were analysed, showing that no P was inserted in the GR. In contrast, very low quantities of P were detected when the analyses were performed on the lateral faces of the GR crystals. Analysis of P in solution by ICP-AES evaluates the quantity of phosphate adsorbed species. A model representing the precipitate and its surface showed that the quantity of adsorbed phosphate has the same order of magnitude than the number of Fe atoms present on the lateral faces. The preference of phosphate species for lateral faces is due to the fact that the {10 (1) over bar0} faces contain mono- and di-coordinated OH- surface groups. PO43- adsorbed on the lateral faces may act as a barrier that slows down the release in solution of the CO32- species preventing GR1(CO32-) to transform into the mixture of Fe3O4 and Fe(OH)(2). (C) 2003 Elsevier SAS. All rights reserved.