用乙醇还原法制备了PVP包裹的Pt纳米颗粒.X射线衍射(XRD)显示了Pt纳米颗粒的衍射谱与块体铂相同.用X射线吸收谱(XAS)对Pt纳米颗粒的近邻结构进行了研究,发现Pt纳米颗粒的配位数和晶胞参数减小.Pt-L_(2,3)"白线"强度增加,模拟纳米颗粒表面效应的XANES计算不能重现Pt-L_(2,3)实验谱,因此作者把"白线"强度的改变归结为Pt纳米颗粒的重构.
The PVP-protected Pt nanoparticles were prepared by ethanol-water reduction method. XRD shows that Pt nanoparticles have the same XRD patterns as bulk Pt except the broaden of XRD peaks. The local structure around Pt was investigated by X-ray absorption spectra and it was found that the coordination numbers and Pt-Pt distances of these nanoparticles decrease. At the same time,we found that the strength of the Pt-L_(2,3) edge "white line" increases,the XANES calculation to simulate the surface effect of nanoparticles can not reproduce the experimental spectrum,so the change of the strength of "white line" is attributed to the rearrange of Pt nanoparticles.
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