Effects of Co and Ni co-doping on the structure and reactivity of hexagonal birnessite
文献类型：期刊论文
| 作者 | Yin, H; Li, H; Wang, Y; Ginder-Vogel, M; Qiu, GH; Feng, XH; Zheng, LR; Liu, F; Zheng LR(郑黎荣)
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| 刊名 | CHEMICAL GEOLOGY
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| 出版日期 | 2014 |
| 卷号 | 381页码:10-20 |
| 关键词 | Manganese oxides Hexagonal birnessite Transition metal Co and Ni co-doping X-ray absorption fine structure spectroscopy |
| 英文摘要 | Natural hexagonal birnessites are enriched in various transition metals (TMs). Many studies have examined the effects of single metal doping on the structures and properties of birnessites, but none focused on the simultaneous interaction mechanism of coprecipitation of two different TMs with birnessite. In this work Co and Ni co-doped hexagonal birnessites were synthesized and characterized by powder X-ray diffraction (XRD), elemental analysis, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) spectroscopy to investigate the effects of co-doping on the structure and reactivity of birnessite and the crystal chemistry of Co and Ni. These co-doped birnessites have lower crystallinity, i.e., fewer manganese layers stacking in the c* direction, larger specific surface areas (SSAs) and increased Mn average oxidation states (AOSs) than the undoped birnessite, and Co exists in a valence of +3. Co, Ni and Mn K-edge extended X-ray absorption fine structure spectroscopy (EXAFS) spectra demonstrate an increase in edge-sharing Ni-Me (Me = Ni, Co and Mn) distances in birnessite layers with the increase of the contents of dopants while Mn-Me distances first decrease and then increase while those of Co-Me pairs are nearly constant, coupled with first a decrease and then increase of the in-plane unit-cell parameter b. The effect of co-doping on the amounts of structural Mn and K+, numbers of [MnO6] layers stacked in c* axis, and SSAs, is larger than the effects of doping with Co alone, but less than singly Ni doping. In birnessites doped with both Co and Ni, similar to 74-79% of the total Co and similar to 23-39% of the total Ni are present within the manganese layers. Compared with the spatial distribution of TM in singly doped birnessites, the coexistence of Ni hinders the incorporation of Co into the layers during birnessite crystallization; however, coprecipitation with Co has little effects, neither hindrance nor promotion, on the insertion of Ni into the layers. These results provide insight into the interaction mechanism between coexisting Co, Ni within layered Mn oxides. It further helps us to interpret the geochemical characteristics of multi-metal incorporation into natural Mn oxides and their effects on the structures and physicochemical properties of these minerals. (C) 2014 Elsevier B.V. All rights reserved. |
| 学科主题 | Geochemistry & Geophysics |
| 收录类别 | SCI |
| WOS记录号 | WOS:000340208500002 |
| 公开日期 | 2016-05-03 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/224882]  |
| 专题 | 中国科学院高能物理研究所 |
| 推荐引用方式 GB/T 7714 | Yin, H,Li, H,Wang, Y,et al. Effects of Co and Ni co-doping on the structure and reactivity of hexagonal birnessite[J]. CHEMICAL GEOLOGY,2014,381:10-20. |
| APA | Yin, H.,Li, H.,Wang, Y.,Ginder-Vogel, M.,Qiu, GH.,...&郑黎荣.(2014).Effects of Co and Ni co-doping on the structure and reactivity of hexagonal birnessite.CHEMICAL GEOLOGY,381,10-20. |
| MLA | Yin, H,et al."Effects of Co and Ni co-doping on the structure and reactivity of hexagonal birnessite".CHEMICAL GEOLOGY 381(2014):10-20. |
入库方式： OAI收割
来源：高能物理研究所
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