Study on Collided Ag or Pt Single Nanoparticle’s Current Peak Shape Changing Depending on Applying Potential

Abstract

Electrocatalytic amplification method was used for analyzing electrochemical properties about collided nanoparticles. Silver nanoparticles (Ag NPs) and platinum nanoparticles (Pt NPs)’s characteristics about hydrazine oxidation reaction were investigated. Those NPs have distinct electrocatalytic activation for hydrazine oxidation reaction. For detecting these NPs, gold (Au) ultramicroelectrode (UME) was used as working electrode which has appropriate catalytic activities comparing with both NPs. When applied potential was above 0 V, Pt NPs showed positive electrocatalytic characteristic, then collided Pt NPs produced amplified transient current signal. In contrast, Ag NPs produced decreased transient current signal when colliding onto Au UME applied above 0.25 V which potential range Ag NPs showed negative electrocatalytic characteristics. But the transient current signals by each collided NPs showed shape shifting as changing applied potential. When applying relatively low potential range, current signals produced by each NPs were staircase shape which means the collided NPs sustain stable state on Au UME after collision events. After changing high potential range, the current signals were shifting to blip or spike shape. As analyzing current peak shape changing phenomenon, electrocatalytic reaction mechanisms by each NPs could be understood by this method.