Nanoparticle Adhesion and the Role of Nanobubbles in Single-Particle Collision Electrochemistry

Herein, we report how the collision and electrocatalytic behavior of single platinum nanoparticles (NPs) can be affected by the transient formation of H 2 nanobubbles generated from the hydrogen evolution reaction (HER). The use of a high concentration of acid (0.5 M HClO 4 ) promotes the nucleation of small nanobubbles, allowing us to observe a dramatic decrease in the collision frequency. Adding surfactant molecules and a defoaming agent to the acid solution causes the collision frequency to further decrease and increase, respectively. These observations support our hypothesis about the critical role of the nanobubble in NP adhesion. Our study further reveals the complex chemical nature of the electrode/NP system and the interesting role of transiently formed gas nanobubbles in determining the adhesion probability of individual NPs on an electrode surface.