Structural Incorporation of As5+ into Hematite

详细信息    查看全文

• 作者：Ralph M. Bolanz ; Maria Wierzbicka-Wieczorek ; M谩ria 膶aplovi膷ov谩 ; Peter Uhl铆k ; J枚rg G枚ttlicher ; Ralph Steininger ; Juraj Majzlan
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：August 20, 2013
• 年：2013
• 卷：47
• 期：16
• 页码：9140-9147
• 全文大小：421K
• 年卷期：v.47,no.16(August 20, 2013)
• ISSN：1520-5851

文摘

Hematite (伪-Fe₂O₃) is one of the most common iron oxides and a sink for the toxic metalloid arsenic. Arsenic can be immobilized by adsorption to the hematite surface; however, the incorporation of As in hematite was never seriously considered. In our study we present evidence that, besides adsorption, the incorporation of As into the hematite crystals can be of great relevance for As immobilization. With the coupling of nanoresolution techniques and X-ray absorption spectroscopy the presence of As (up to 1.9 wt %) within the hematite crystals could be demonstrated. The incorporated As⁵⁺ displays a short-range order similar to angelellite-like clusters, epitaxially intergrown with hematite. Angelellite (Fe₄As₂O₁₁), a triclinic iron arsenate with structural relations to hematite, can epitaxially intergrow along the (210) plane with the (0001) plane of hematite. This structural composite of hematite and angelellite-like clusters represents a new immobilization mechanism and potentially long-lasting storage facility for As⁵⁺ by iron oxides.