In situ TEM observation of Au–Cu2O core–shell growth in liquids. Issue 21 (21st May 2019)

• Record Type: Journal Article
• Authors: Chen, Fu-Chun; Chen, Jui-Yuan; Lin, Ya-Hsuan; Kuo, Ming-Yu; Hsu, Yung-Jung; Wu, Wen-Wei
• Is Part Of: Nanoscale. Volume 11:Issue 21(2019)
• Page Start: 10486
• Page End: 10492
• Publication Date: 2019-05-21
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c9nr00972h
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The formation of different shapes Au–Cu2 O core–shell nanoparticles was investigated by in situ liquid cell transmission electron microscopy (LCTEM). Abstract : Heterogeneous nanoparticles are widely used in catalysis, sensors and biology due to their versatile functions. Among the various heterogeneous nanoparticles, Au–Cu2 O core–shell nanoparticles show high stability and short response times for use as sensors and catalysts and have thus attracted much attention. Previous studies show that the properties of Au–Cu2 O are mainly related to the shape and size of the Au–Cu2 O nanoparticles. However, the forming behavior of heterostructures and the mechanism have not been fully explored. In this work, liquid cell transmission electron microscopy (LCTEM) was used to investigate the formation of these interesting Au–Cu2 O nanoparticles and their process of aggregation. The electron beam and dispersion of gold nanoparticles are both important parameters for the reduction reaction in in situ LCTEM. The Au–Cu2 O core–shell nanoparticles can be synthesized to have two morphologies, multifaceted and cubic. The nanoparticles grew into these different morphologies due to the amount of remaining citrate ligands on the surface of the gold nanoparticles. For the multifaceted nanoparticles, the epitaxy of the two components is confirmed from high-resolution TEM images and electron diffraction patterns with an epitaxial relationship of Au (020)//Cu2 O (020) and Au [101]//Cu2 O [101]. The growth rate is approximately 210 nm 2 s −1 . On the other hand, the cubic nanoparticles nucleate and grow independently. The growth kinetics and elemental distributions have been systematically studied. In addition, the nanoclusters would float, rotate, and finally aggregate with the surrounding clusters. This in situ experiment sheds light on the growth mechanisms of nanostructures and will improve the applicability and controllability of heterostructure synthesis.