Collision and Oxidation of Silver Nanoparticles on a Gold Nanoband Electrode

Abstract

We report the use of gold nanoband electrodes ranging from 60 to 180 nm in width to study collision and oxidation of single Ag nanoparticles (NPs). The use of nanoscale electrodes has enabled the observation of unique single-NP collision responses indicating a strong electrode size effect when the critical dimension of the electrode (the bandwidth) is reduced to that of NPs. In addition to multipeak events, NP collision on a nanoband electrode displays reduced collision frequency, significantly higher probability of single-peak events, and fewer subpeaks. More importantly, the average charge transferred in a single-peak event is about 50% less than that of the first subpeak of a multipeak event. The reduced charge of single-peak collisions and the more frequent appearance on nanoelectrodes are strong evidence that NPs start to behave differently at the electrode/solution interface when the size of the electrode is reduced to be comparable to that of the NPs. The reduced charge is likely due to a weaker pa...