Minkyung Kang, David Perry, Yang-Rae Kim, Alex W. Colburn, Robert A. Lazenby, Patrick R. Unwin*

Journal of the American Chemical Society 2015, 137(34), 10902−10905
 
Publication online: August 12, 2015
Publication date: September 2, 2015
DOI: 10.1021/jacs.5b05856
ISSN: 0002-7863
Journal country: United States
Publisher: AMER CHEMICAL SOC
URL: http://pubs.acs.org/doi/abs/10.1021/jacs.5b05856
 

Abstract: There is considerable interest in understanding the interaction and activity of single entities, such as (electro)catalytic nanoparticles (NPs), with (electrode) surfaces. Through the use of a high bandwidth, high signal/noise measurement system, NP impacts on an electrode surface are detected and analyzed in unprecedented detail, revealing considerable new mechanistic information on the process. Taking the electrocatalytic oxidation of H2O2 at ruthenium oxide (RuOx) NPs as an example, the rise time of current–time transients for NP impacts is consistent with a hydrodynamic trapping model for the arrival of a NP with a distance-dependent NP diffusion-coefficient. NP release from the electrode appears to be aided by propulsion from the electrocatalytic reaction at the NP. High-frequency NP impacts, orders of magnitude larger than can be accounted for by a single pass diffusive flux of NPs, are observed that indicate the repetitive trapping and release of an individual NP that has not been previously recognized. The experiments and models described could readily be applied to other systems and serve as a powerful platform for detailed analysis of NP impacts.

 

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