Center for Nanoscale Science and Technology, National Institute of Standards and Technology (NIST) , Gaithersburg, Maryland 20899, United States.
Maryland NanoCenter, University of Maryland , College Park, Maryland 20742, United States.
Anal Chem. 2017 Mar 7;89(5):2687-2691. doi: 10.1021/acs.analchem.7b00210. Epub 2017 Feb 13.
Concurrent mapping of chemical reactivity and morphology of heterogeneous electrocatalysts at the nanoscale allows identification of active areas (protrusions, flat film surface, or cracks) responsible for productive chemistry in these materials. Scanning electrochemical microscopy (SECM) can map surface characteristics, record catalyst activity, and identify chemical products at solid-liquid electrochemical interfaces. It lacks, however, the ability to distinguish topographic features where surface reactivity occurs. Here, we report the design and fabrication of scanning probe tips that combine SECM with atomic force microscopy (AFM) to perform measurements at the nanoscale. Our probes are fabricated by integrating nanoelectrodes with quartz tuning forks (QTFs). Using a calibration standard fabricated in our lab to test our probes, we obtain simultaneous topographic and electrochemical reactivity maps with a lateral resolution of 150 nm.
在纳米尺度上对非均相电催化剂的化学反应性和形态进行同时映射，可以确定这些材料中负责产生有价值化学反应的活性区域（突出物、平整膜表面或裂缝）。扫描电化学显微镜（SECM）可以绘制表面特征，记录催化剂活性，并在固液电化学界面处识别化学产物。然而，它无法区分发生表面反应的地形特征。在这里，我们报告了设计和制造扫描探针的方法，该探针将 SECM 与原子力显微镜（AFM）相结合，以在纳米尺度上进行测量。我们的探针是通过将纳米电极与石英音叉（QTF）集成来制造的。使用我们实验室中制造的校准标准品来测试我们的探针，我们获得了具有 150nm 横向分辨率的同时的形貌和电化学反应性图谱。
