An EXAFS Study on the Local Structure Around Iron in Atmospheric Aerosols Collected in the Qingdao Area

Molecules

Jianhua Qi¹  Manping Zhang¹  Lijuan Feng¹  Xianguo Li¹  Zhi Xie²  Zhihu Sun² 

[1] College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266003, P. R. China;Hefei Synchrotron Radiation Facility, University of Science and Technology of China, Heifei 230029, P. R. China

关键词: Atmospheric aerosol;    EXAFS;    iron speciation;    Qingdao.;   

DOI  :  10.3390/80100031

来源: mdpi

【 摘 要 】

The existing forms of Fe are of great interest since they have a profound effect on the biological availability of Fe. In this work, aerosol samples collected in different seasons and at different locations in the Qingdao region were examined by means of extended X-ray absorption fine structure (EXAFS) K-edge analysis of Fe, X-ray diffraction (XRD) and Fe content analysis. The results showed that an iron ion in aerosol particles is surrounded on average by 5.8 (coordinated) O ions. For the six samples examined, the coordination number of the first Fe-O coordination subshell is always 3 with a coordination distance (with O) in the range of 1.952~1.966±0.002 Å, while the coordination number of the second subshell varies from 2.2 to 3.0 with a coordination distance of 2.108±0.002 Å. The coordination is approximately consistent with that of α-Fe₂O₃, suggesting that iron in aerosol samples is mainly present in the form of α-Fe₂O₃. The fact that the coordination number in the second subshell is smaller than that of α-Fe₂O₃ might be an indication that there is a small amount of FeO mixed with α-Fe₂O₃ in aerosol particles. Existence of FeO is confirmed by a later XRD experiment.

【 授权许可】

Unknown   
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