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

Pradeep Doggali,Dinesh K Mahalingam,Nitin M Batra,Suzana P Nunes,Pedro M F J Costa

doi:10.1088/1361-6528/ac547c

Abstract

In recent years, graphene has been explored as a heating membrane for studying high-temperature dynamics inside the transmission electron microscope (TEM) due to several limitations with the existing silicon nitride-based membrane. However, the transfer of monolayer graphene films for TEM experiments is challenging and requires many complicated steps with a minimum success rate. This work developed a novel in situ heating platform by combining the graphene oxide (GO) flakes in the pre-patterned chips. The isolated GO flake was self-suspended between the metal electrodes by a simple drop-casting process. The GO was reduced and characterized using Raman and electron energy-loss spectroscopy. Furthermore, a GO-based heater was used to investigate the thermal stability of gold and silica nanoparticles. The gold nanoparticles evaporated non-uniformly and left an empty carbon shell, while silica disappeared uniformly by etching carbon support. We successfully demonstrated a GO flake as a heating membrane to study high temperature thermal dynamic reactions: melting/evaporation, agglomeration, Rayleigh instability, and formation/or removal of carbon in the nanoparticles.

Highlights

Introduction anFor studying dynamics reactions of nanomaterials at high temperatures, specially designed environmental transmission electron microscope (TEM) and in-situ TEM holders are commonly used
Graphene has been explored as a heating membrane for studying high-temperature dynamics inside the transmission electron microscope (TEM) due to several limitations with the existing silicon nitride-based membrane
We successfully demonstrated a graphene oxide (GO) flake as a heating membrane to study high temperature thermal dynamic reactions: melting/evaporation, agglomeration, Rayleigh instability, and formation/or removal of carbon in the nanoparticles

Summary

Introduction

For studying dynamics reactions of nanomaterials at high temperatures, specially designed environmental transmission electron microscope (TEM) and in-situ TEM holders are commonly used. [1–8] The in-situ holders use engineered silicon nitride membrane-based chips.[9,10] These silicon nitride-based chips suffered several limitations: thicker support membrane, poor contract, hightemperature instability, thermal drift, and membrane degradation above >1100 oC.[11,12]. An electron transparent and atomically thin material, is the ideal candidate for TEM support film. Resolved images are acquired from nanomaterials supported on the graphene under static and dynamic conditions.[13–15]. The final steps to place graphene on a target substrate are delicate, as the transfer steps involve various manual interventions and chemicals.[12,16,17]. These factors prohibit its use in commercial heating chips The final steps to place graphene on a target substrate are delicate, as the transfer steps involve various manual interventions and chemicals.[12,16,17] These factors prohibit its use in commercial heating chips

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