Probing Surface Electrochemical Activity of Nanomaterials using a Hybrid Atomic Force Microscope-Scanning Electrochemical Microscope (AFM-SECM)
Dr. Wen Zhang’s group in New Jersey Institute of Technology published a video article in Journal of Visualized Experiments (JOVE). They reported the application of a combination of atomic force microscopy (AFM) and scanning electrochemical microscopy (SECM), namely, AFM-SECM, to probe nanoscale surface electrochemical activity while acquiring high-resolution topographical data. SECM is used to measure the local electrochemical behavior of liquid/solid, liquid/gas and liquid/liquid interfaces. AFM is a versatile tool to characterize micro- and nanostructure in terms of topography and mechanical properties. However, conventional SECM or AFM provides limited laterally resolved information on electrical or electrochemical properties at nanoscale. For instance, the activity of a nanomaterial surface at crystal facet levels is difficult to resolve by conventional electrochemistry methods. The measurements performed in this paper are critical to understanding the relationship between nanostructure and reaction activity, which is relevant to a wide range of applications in material science, life science and chemical processes. The versatility of the combined AFM-SECM is demonstrated by mapping topographical and electrochemical properties of faceted nanoparticles (NPs) and nanobubbles (NBs), respectively. Compared to previously reported SECM imaging of nanostructures, this AFM-SECM enables quantitative assessment of local surface activity or reactivity with higher resolution of surface mapping.
Dr. Wen Zhang’s group in New Jersey Institute of Technology published a video article in Journal of Visualized Experiments (JOVE). They reported the application of a combination of atomic force microscopy (AFM) and scanning electrochemical microscopy (SECM), namely, AFM-SECM, to probe nanoscale surface electrochemical activity while acquiring high-resolution topographical data. SECM is used to measure the local electrochemical behavior of liquid/solid, liquid/gas and liquid/liquid interfaces. AFM is a versatile tool to characterize micro- and nanostructure in terms of topography and mechanical properties. However, conventional SECM or AFM provides limited laterally resolved information on electrical or electrochemical properties at nanoscale. For instance, the activity of a nanomaterial surface at crystal facet levels is difficult to resolve by conventional electrochemistry methods. The measurements performed in this paper are critical to understanding the relationship between nanostructure and reaction activity, which is relevant to a wide range of applications in material science, life science and chemical processes. The versatility of the combined AFM-SECM is demonstrated by mapping topographical and electrochemical properties of faceted nanoparticles (NPs) and nanobubbles (NBs), respectively. Compared to previously reported SECM imaging of nanostructures, this AFM-SECM enables quantitative assessment of local surface activity or reactivity with higher resolution of surface mapping.
Figure: Simultaneously acquired topography (A) and tip current (B) images of Cu2O nanoparticles in electrolyte containing 10 mM [Ru(NH3)6]3+and 0.1 M KCl. The tip with a tip radius of 25 nm was biased at -0.4V. (C) Schematic illustration of AFM-SECM measurement of NPs.