论文标题
通过簇分析,薄膜催化剂中缺陷的X射线纳米成像
X-ray Nano-imaging of Defects in Thin Film Catalysts via Cluster Analysis
论文作者
论文摘要
过渡金属氧化物的功能特性在很大程度上取决于晶体学缺陷。在诸如SRIRO3(SIO)之类的过渡金属氧化物电催化剂中,晶体学晶格偏差会影响离子扩散和吸附的结合能。扫描X射线纳米施法可以对薄样品的扩展空间区域进行局部结构畸变的成像。由于纳米式散射弱散射,线缺陷在使用纳米式曲线的检测和本地化方面仍然具有挑战性。在这里,我们应用了一种无监督的机器学习聚类算法,以分离出生长的和碱处理的薄薄薄膜薄膜中的低强度弥散散射。我们确定缺陷位置,在电化学上循环SIO的形态中找到其他应变变化,并通过通过聚类来分析衍射谱来解释缺陷类型。我们的发现表明,使用机器学习聚类算法来识别和表征电催化剂薄膜中难以找到的晶体学缺陷,并突出了在操作数实验中缺陷位点研究电化学反应的潜力。
Functional properties of transition-metal oxides strongly depend on crystallographic defects. In transition-metal-oxide electrocatalysts such as SrIrO3 (SIO), crystallographic lattice deviations can affect ionic diffusion and adsorbate binding energies. Scanning x-ray nanodiffraction enables imaging of local structural distortions across an extended spatial region of thin samples. Line defects remain challenging to detect and localize using nanodiffraction, due to their weak diffuse scattering. Here we apply an unsupervised machine learning clustering algorithm to isolate the low-intensity diffuse scattering in as-grown and alkaline-treated thin epitaxially strained SIO films. We pinpoint the defect locations, find additional strain variation in the morphology of electrochemically cycled SIO, and interpret the defect type by analyzing the diffraction profile through clustering. Our findings demonstrate the use of a machine learning clustering algorithm for identifying and characterizing hard-to-find crystallographic defects in thin films of electrocatalysts and highlight the potential to study electrochemical reactions at defect sites in operando experiments.