Measuring the activation energy barrier for the nucleation of single nanosized vapor bubbles

Abstract

Heterogeneous bubble nucleation is one of the most fundamental interfacial processes that has received broad interest from diverse fields of physics and chemistry. While most studies focused on large microbubbles, here we employed a surface plasmon resonance microscopy to measure the nucleation rate constant and activation energy barrier of single nanosized embryo vapor bubbles upon heating a flat gold film with a focused laser beam. Image analysis allowed for simultaneously determining the local temperature and local nucleation rate constant from the same batch of optical images. By analyzing the dependence of nucleation rate constant on temperature, we were able to calculate the local activation energy barrier within a submicrometer spot. Scanning the substrate further led to a nucleation rate map with a spatial resolution of 100 nm, which revealed no correlation with the local roughness. These results indicate that facet structure and surface chemistry, rather than geometrical roughness, regulated the activation energy barrier for heterogeneous nucleation of embryo nanobubbles.

Imaging and Quantifying the Formation of Single Nanobubbles at Single Platinum Nanoparticles during the Hydrogen Evolution Reaction

“…If the earliest label-free imaging of HER at Pt NPs by SPRM suggested I opt changes were due to local molecular H + or dissolved H 2 concentration gradient around catalytic NPs, 41 we believe such change results from H 2 gas NB formation, as demonstrated later by White et al, who showed that single gas NBs can nucleate and grow from electrochemical reactions at nanoelectrodes. 6 The optical visualization of NBs on surfaces was further confirmed (i) from fluorescence imaging (rigorously of the NBsolution interface) during HER at electrode surface or NPs, or (ii) from label-free imaging of gas NBs, either by SPRM at heated surfaces 27,42 or dark field microscopy for qualitative benchmarking of NPs electrocatalytic activity. 3,43 We explore here the possibility of analyzing quantitatively the NBs formation from the variations of the local optical intensity, I opt , recorded by IRM.…”

“…the wetting of the NP). 27 Surface chemistry could play similarly a significant role in the overall electrochemical activity of the NP. The capping agent of the NP is expected to control both the electrical contact between the NP and the electrode and the electron transfer rate for HER at the NP-solution interface.…”

The Localized Enhancement of Surface Plasmon Standing Waves Interacting with Single Nanoparticles

“…Single nanoparticles induce the localized enhancement of SPPs, and transforms to far field via leakage radiation for fast and label-free detection [5,6]. This method has been widely applied to chemistry and biology, such as bidirectional electron transfers visualizing [7], local activation energy barrier measuring [8], thermal hysteresis imaging of single spin-crossover nanoparticles [9], and single liposomes and virus detection [10][11][12].…”

In-Situ Plasmonic Tracking Oxygen Evolution Revealing Multistage Oxygen Diffusion and Accumulating Inhibition

“…Plasmonic-enhanced spectroscopy 18,19 exploits the excellent optical performance of advanced plasmonic nanostructures and possesses noninvasive feature with superior sensitivity and compatibility in monitoring a variety of chemical processes, including heterogeneous catalysis [20][21][22] , electrochemistry [23][24][25] and phase transition [26][27][28] . Thereby, plasmonic-enhanced spectroscopy may possess the ability to differentiate oxygen compositions during OER at EEIs.…”