Fabrication of Scanning Electrochemical Microscopy-Atomic Force Microscopy (SECM-AFM) Probes to Image Surface Topography and Reactivity at the Nanoscale

摘要

Electrocatalysts, used in energy applications, rely on the solid-liquid interface to carry out productive chemistry. This interface is generally less amenable to standard surface-science characterization methods, making the investigation of the surface activity, catalyst structure and chemical evolution at the nanoscale very challenging. Bulk measurements have been applied, but these lack sufficient resolution to identify conclusively which structures (protrusions, flat film surface, or cracks) are responsible for chemistry in these materials. In order to address these questions, we have designed and fabricated scanning probe tips for combined atomic force microscopy (AFM) and scanning electrochemical microscopy (SECM). AFM combined with SECM provides a direct correlation of topological information with the chemical surface reactivity, at a resolution defined by the probe radius. The structure/activity correlations obtained will reveal underlying reaction mechanisms that enable engineering of more active materials.