Tuning the Electrode Activity to Expose Transformational and Electrocatalytic Characteristics of Individual Nanoparticles by Nanoimpact Electrochemistry

Abstract

Nanoimpact electrochemistry (NIE) is a straightforward analytical technique to study at high throughput the reactivity of single nanoparticles (NPs) colliding with a biased ultramicroelectrode (UME). As NIE can reveal both NP size and catalytic activity, this strategy can be employed to establish relationships between these two NP descriptors. Herein, it is shown that the electrode material is crucial for visualizing simultaneously electrocatalytic processes and NP transformation, which can size the NPs. UMEs made of gold (Au) or glassy carbon (GC), were employed to study the reduction of AgBr NPs and the electrocatalytic activity of the resulting Ag NPs for the oxygen reduction reaction (ORR). With Au UME, only the transformation process is probed, allowing a quantitative analysis of the overpotential effect on the reduction dynamics of the AgBr NPs. When a GC UME is employed, the AgBr NPs reduction and subsequent ORR activity can be quantified for the very same NPs.

Single Entity Electrocatalysis

“…These results with other insights from different electrodes and different potentials were able to provide greater mechanistic insights into the electrocatalysis at the nanoparticles. Furthermore, Sepanaru’s experiments inspired further work by Kanoufi and Noël, who used different electrode materials and demonstrated the reduction of AgBr particles to Ag, on which ORR could be studied …”

“…Furthermore, Sepanaru's experiments inspired further work by Kanoufi and Noel, who used different electrode materials and demonstrated the reduction of AgBr particles to Ag, on which ORR could be studied. 132 4.2.1.3. Nonmetallic Single Entities.…”

“…Coulometry can be used to size particles , , examine single-nanoparticle electrochemical activity, and explore transformative nano-impact analysis. In each case, the stochastic collision of the nanoparticle with the electrode may result in some modification to the particle including complete or partial reduction/oxidation , of the metal nanoparticle or modification/deactivation by ions (especially in the case of silver nanoparticles − ). Anodic stripping has also been performed on the single nanoparticle level. , Other relevant modifications that can be measured by stochastic electrochemistry include quantification of lithiation and other ion insertion kinetics.…”