Time-Resolved Detection and Analysis of Single Nanoparticle Electrocatalytic Impacts.
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.
Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K.
Minkyung
M
Kang
Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K.
David
D
Perry
Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K.
Yang-Rae
YR
Kim
Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K.
Alex W
AW
Colburn
Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K.
Robert A
RA
Lazenby
Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K.
Patrick R
PR
Unwin