Observation of Electrocatalytic Amplification of Iridium Oxide (IrO_x) Single Nanoparticle Collision on Copper Ultramicroelectrodes

Abstract

Recently, the observation of the electrocatalytic behavior of individual nanoparticles (NPs) by electrochemical amplification method has been reported. For example, the Iridium oxide (IrO x ) NP collision on the Pt UME was observed via electrocatalytic water oxidation. However, the bare Pt UME had poor reproducibility for the observation of NP collision signal and required an inconvenient surface pre-treatment for the usage. In this manuscript, we has been investigated other metal electrode such as Cu UME for the reproducible data analysis and convenient use. The IrO x NP collision was successively observed on the bare Cu UME and the reproducibility in collision frequency was improved comparing with previous case using the NaBH 4 pre-treated Pt UME. Also, the adhesion coefficient between NP and the Cu UME was studied for better understanding of the single NP collision system.

Single Palladium Nanoparticle Collisions Detection through Chronopotentiometric Method: Introducing a New Approach to Improve the Analytical Signals

“…In recent years a number of reviews has been published in the field of nano impact. , Scientists have used several methods to observe the impact of nanoparticles on the electrode surface. These methods include electrocatalytic current amplification (ECA), , potentiometric method, anodic particle coulometry (APC), cathodic particle coulometry (CPC), and blocking method . Beside determining the size distribution of nanoparticles, these methods are able to estimate their surface activity .…”

Electrochemical Detection and Analysis of Various Current Responses of a Single Ag Nanoparticle Collision in an Alkaline Electrolyte Solution

“…The collision mechanism of a single NP collision can be classified as hit-n-run, hit-n-roll, or hit-n-stay, depending on the state of the NP after the collision event [7]. In particular, when Cu was used as a UME to observe the single-NP collision signals of Pt NPs and IrO x NPs, it was observed that the collision frequency was significantly reduced to ~1/3000 for Pt NPs and ~1/4 for IrO x NPs compared to the other electrode materials [38,39]. Therefore, we believe that the reduced frequencies are because of the weak interaction between the NPs and Cu UME, which leads to a hit-n-run mechanism in which the colliding Ag NP does not adhere well to the Cu UME.…”