Dynamic processes of hybrid nanostructured Au particles/nanobubbles in a quasi-2D system by in-situ liquid cell TEM

Abstract

Recently hybrid structure of hydrogen nanobubble (HNB) and gold nanoparticles (GNP) have attracted a great deal of interest in many potential applications including ultrasound contrast agent, cancer therapy and drug delivery. For the first time, here we reported interaction of high energy electron beam with sodium citrate catalyzes a highly stable hybrid super structure (HNB ∈ Au) where sub-nanometer sized GNPs are decorated on the HNB surface. The formation mechanism of HNB ∈ Au has been in-depth studied in this work. This electron radiation technique is the easiest method for the large-scale production of environmentally benign sub-nanometer sized GNP and HNB at room temperature. We have successfully demonstrated the HNB can serve as a substrate or a template for attracting Au nano-clusters onto its surface by in-situ transmission electron microscopy in liquid environment. The kinetics of multiple coalescence process of merging ultra-small GNP and HNB has been analyzed with Mehl-Avrami-Kolmogorov (JMAK) scheme. It suggests that the growth modes for HNB and GNP in the formation process of HNB ∈ Au are 2D and 3D, respectively. Here we have also calculated the momentum transferred to the GNP from the incident electrons and surrounding liquid molecules. It indicates that the incident electrons can trigger the GNP sliding on HNB surface at relatively high dose rate.