Crozier Peter A, Aoki Toshihiro, Liu Qianlang
School for the Engineering of Matter, Transport and Energy, Arizona State University, 501 E. Tyler Mall, Tempe, AZ 85287-6106, USA.
LeRoy Eyring Center for Solid State Science, Arizona State University, Tempe, AZ 85287-1704, USA.
Ultramicroscopy. 2016 Oct;169:30-36. doi: 10.1016/j.ultramic.2016.06.008. Epub 2016 Jun 24.
Understanding the role of water, hydrate and hydroxyl species on nanoparticle surfaces and interfaces is very important in both physical and life sciences. Detecting the presence of oxygen-hydrogen species with nanometer resolution is extremely challenging at present. Here we show that the recently developed vibrational electron energy-loss spectroscopy using subnanometer focused electron beams can be employed to spectroscopically identify the local presence and variation of OH species on nanoscale surfaces. The hydrogen-oxygen fingerprint can be correlated with highly localized structural and morphological information obtained from electron imaging. Moreover, the current approach exploits the aloof beam mode of spectral acquisition which does not require direct electron irradiation of the sample thus greatly reducing beam damage to the OH bond. These findings open the door for using electron microscopy to probe local hydroxyl and hydrate species on nanoscale organic and inorganic structures.
了解水、水合物和羟基物种在纳米颗粒表面和界面上的作用在物理科学和生命科学中都非常重要。目前，以纳米分辨率检测氧氢物种的存在极具挑战性。在此，我们表明，最近开发的使用亚纳米聚焦电子束的振动电子能量损失光谱可用于光谱识别纳米级表面上OH物种的局部存在和变化。氢氧指纹可以与从电子成像获得的高度局部化的结构和形态信息相关联。此外，当前方法利用了光谱采集的远离束模式，该模式不需要对样品进行直接电子照射，从而大大减少了对OH键的束损伤。这些发现为利用电子显微镜探测纳米级有机和无机结构上的局部羟基和水合物物种打开了大门。
