Optical monitoring of the electrochemical nucleation and growth of silver nanoparticles on electrode: From single to ensemble nanoparticles inspection

Abstract

The electrochemical nucleation and growth of nanoparticles (NPs) on an electrode surface at a constant potential is traditionally followed by recording the resulting current density during the experiment. The obtained chronoamperometric transients are average measurements, making it difficult to separate individual NP behaviors and to study their cross-talks. Herein, the recently developed Backside Absorbing Layer Microscopy (BALM) is employed to monitor optically in situ and operando the electrodeposition of silver NPs. This latter technique exploits a pseudo-antireflective and metallic contrast layer and allows both sub-nanometer vertical and sub-micrometer spatial resolutions. The information from the recorded movies is readily exploited to study the NP electrodeposition at the single entity level. The image sequences allow quantifying the local electrodeposition of nanomaterials onto the electrode surface, probing the NP dynamics through the extraction of single optical NP growth transients, and analyzing the effect of the neighboring nuclei on the growth of individual NPs.