Department of Geosciences, Stony Brook University, Stony Brook, New York 11794, USA.
Inorg Chem. 2010 Jan 4;49(1):325-30. doi: 10.1021/ic9022695.
Differential pair distribution function (d-PDF) analysis of high energy powder X-ray diffraction data was carried out on 2-line ferrihydrite nanoparticles with arsenate oxyanions adsorbed on the surface to investigate the binding mechanism. In this analysis, a PDF of ferrihydrite is subtracted from a PDF of ferrihydrite with arsenate sorbed on the surface, leaving only correlations from within the surface layer and between the surface and the particle. As-O and As-Fe correlations were observed at 1.68 and 3.29 A, respectively, in good agreement with previously published EXAFS data, confirming a bidentate binuclear binding mechanism. Further peaks are observed in the d-PDF which are not present in EXAFS, corresponding to correlations between As and O in the particle and As-2nd Fe.
采用高能量粉末 X 射线衍射数据的差分对分布函数（d-PDF）分析方法，对吸附在表面的砷酸盐氧阴离子的 2 线水铁矿纳米粒子进行了研究，以探讨其结合机制。在该分析中，从吸附在表面的砷酸盐的水铁矿 PDF 中减去水铁矿 PDF，只留下来自表面层内和表面与颗粒之间的相关性。在 1.68 和 3.29Å 处分别观察到 As-O 和 As-Fe 相关性，与先前发表的 EXAFS 数据非常吻合，证实了双齿双核结合机制。在 d-PDF 中还观察到一些在 EXAFS 中不存在的峰，对应于颗粒中和 As-2ndFe 中 As 与 O 之间的相关性。
