Single Nanoparticle Voltammetry: Contact Modulation of the Mediated Current

Abstract

The cyclic voltammetric responses of individual palladium‐coated carbon nanotubes are reported. Upon impact—from the solution phase—with the electrified interface, the nanoparticles act as individual nanoelectrodes catalyzing the hydrogen‐oxidation reaction. At high overpotentials the current is shown to reach a quasi‐steady‐state diffusion limit, allowing determination of the tube length. The electrochemical response of the individual nanotubes also reveals the system to be modulated by the electrical contact between the electrode and carbon nanotube. This modulation presents itself as fluctuations in the recorded Faradaic current.

Palladium nanoparticles supported on graphene sheets incorporating boron oxides (BxOy) for enhanced formic acid oxidation

“…When Pd salt precursors interact with BG, the active sites caused by BxOy incorporation will work as anchoring points to fix salt precursors. After metal ions coordinated with BG, hydrolysis was applied to crystallize the precursors nucleated on the BxOy incorporated graphene sheets to form nanocrystals [24,25]. Meanwhile, the interaction between Pd and BxOy modified graphene sheets can restrain the growth of Pd particles during reduction process.…”

Semiconducting Nanoparticles: Single Entity Electrochemistry and Photoelectrochemistry

“…This powerful electrochemical technique has found much strength in giving insights into the fundamental study of nanoparticles: not only the basic particle characterization (e.g. sizing, concentration, chemical identity, agglomeration/aggregation state, porosity) ( Zhou et al, 2011 ; Stuart et al, 2012 ; Tschulik et al, 2014 ; Jiao et al, 2017 ; Li et al, 2019 ), but also in-depth understanding at single-particle levels for the mechanisms and dynamics of (photo) electrochemical processes of interest ( Xiao and Bard, 2007 ; Bard et al, 2010 ; Fernando et al, 2013 ; Li et al, 2016 ; Ma et al, 2018 ; Peng et al, 2018 ).…”

Substrate mediated dissolution of redox active nanoparticles; electron transfer over long distances

“…For example, stripping voltammetry is commonly used to study the effects of particle apparent size [15], agglomeration [16], coverage [17] and assembly methods [18] on the nanoparticle oxidation. In this way, the influence of electrolyte [19] and the interactions of the metal NPs with the substrate electrode [20] or their attached surface functional groups have also been investigated [21]. Such electrochemical methods necessarily require the polarisation of the electrode to drive/control the particles' oxidation.…”