In Situ Transmission Electron Microscopy Investigation of Melting/Evaporation Kinetics in Anisotropic Gold Nanoparticles

Abstract

We report on thermal stability and phase transition behaviors of triangular Au nanoprisms through in situ heating transmission electron microscopy. With rising temperature, Au nanoprisms exhibit fluctuating surface reconstructions at the corner regions. When a quasi-melting state is reached at the temperature below bulk melting points, the evaporation is initiated commonly at a corner with low curvature and containing sharp intersection points. The subsequent annealing process leads to the gradual evaporation, which, in the absence of thick carbon coverages, is accompanied by marked shape reconstructions. The thermal stability and evaporation behaviors are not evidently regulated by nanoprism aggregations.

Gold@Carbon Nitride Yolk and Core–Shell Nanohybrids

“…This partial deformation of the Au NP shape is attributed to the high temperature that is required for the calcination of g-C 3 N 4. Temperature sensitivity and reshaping of Au nanostructures were previously reported in the literature. , …”

“…Temperature sensitivity and reshaping of Au nanostructures were previously reported in the literature. 57,58 2.4. Nanohybrid Structural Characterization.…”

Investigating the thermal stability of metallic and non-metallic nanoparticles using a novel graphene oxide-based transmission electron microscopy heating-membrane

“…In the literature, most of the experiments were performed at constant temperature after initiation of evaporation/sublimation. Therefore, the rate of evaporation/sublimation of nanoparticle was slower in those cases [38,41,45].…”

“…In this work, evaporation of Au nanoparticles occurred above 950 °C as confirmed by ex situ and in situ studies. In recent work, Liu et al found that melting/evaporation of prismshaped Au nanoparticles took place at 875 °C using commercial heating chips [38]. Hobbs calculations showed that the temperature rise due to electron beam-induced heating is negligible in highly conductive samples [39].…”