Probing the sublimation kinetics of Ag, Ag@TiO2, and Ag@C nanoparticles

• Published in: Nanoscale Vol. 15; no. 17; pp. 7722 - 7729
• Main Authors: Huang, Hao-Chin, Hsiao, Kai-Yuan, Tseng, Yu-Han, Chen, Yan-De, Lu, Ming-Yen
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 04.05.2023
• Subjects: Core-shell structure; Heating; High temperature effects; Low temperature; Morphology; Nanoparticles; Silver; Sublimation; Thermal stability; Titanium dioxide
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/d3nr00258f

In this study, we used an in situ transmission electron microscopy (TEM) heating system to investigate the sublimation-induced morphological changes of cubic Ag nanoparticles (NPs) and Ag-based core–shell structures and the influence of shell coverage on the thermal stability. In contrast to previous research performed with small Ag nanoparticles (<30 nm), here we found that large-particle Ag NPs (>50 nm) underwent a three-stage sublimation-induced morphological change at 800 °C, in the sequence uniform (I)–nonuniform (II)–uniform (III) sublimation. The (110) and (100) planes were the main sublimation planes during stages I and II. When the reaction reached stage III, the sublimation rate decreased as a result of an increase in the sublimation energy barrier. For core–shell NPs, the sublimation process began with stage II. For Ag NPs presenting TiO2 shells, the sublimation process was initiated at a relatively low temperature (700–750 °C) because of a local heating effect; for Ag NPs with carbon shells, the reaction was suppressed through surface atom passivation, thereby enhancing the thermal stability.