Premium
Monitoring Simultaneous Electrochemical Reactions with Single Particle Imaging
Author(s) -
Sundaresan Vignesh,
Monaghan Joseph W.,
Willets Katherine A.
Publication year - 2018
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201800715
Subject(s) - electrochemistry , nanoclusters , particle (ecology) , anode , materials science , nanoparticle , ion , particle size , chemical engineering , analytical chemistry (journal) , nanotechnology , inorganic chemistry , chemistry , electrode , organic chemistry , oceanography , geology , engineering
Studying multiple simultaneous electrochemical reactions using typical electrochemical methods is challenging, because the measured current is a convolution of concurrent electrochemical reactions. Thus, to monitor multiple simultaneous electrochemical reactions, secondary techniques, such as imaging or spectroscopy are increasingly useful. Herein we use dark‐field optical microscopy to visualize the electrodeposition of silver oxide (Ag x O y ) particles using the Ag + ions generated by the concurrent electrodissolution of individual Ag nanoparticles at high anodic potential. We propose that the formation of Ag x O y particles is based on an aggregative growth mechanism, where electrodeposited Ag x O y nanoclusters aggregate over time to form a larger Ag x O y particle. The electrodeposited Ag x O y particles catalyze water oxidation and decrease the local pH, which alters the reaction equilibrium by hindering continued growth of the Ag x O y particles at 1.2 V and consuming the Ag x O y particles and producing Ag + ions at open circuit. Overall the understanding obtained by imaging these reactions is not possible to decode using the measured ensemble current.