Atomic and nanoscale imaging of a cellulose nanofiber and Pd nanoparticles composite using lower-voltage high-resolution TEM

Megumi Ohwada; Yoshiteru Mizukoshi; Tomoko Shimokawa; Noriko Hayashi; Yuichiro Hayasaka; Toyohiko J Konno

doi:10.1093/jmicro/dfx021

Atomic and nanoscale imaging of a cellulose nanofiber and Pd nanoparticles composite using lower-voltage high-resolution TEM

Microscopy (Oxf). 2017 Oct 1;66(5):348-355. doi: 10.1093/jmicro/dfx021.

Authors

Megumi Ohwada¹, Yoshiteru Mizukoshi¹, Tomoko Shimokawa², Noriko Hayashi², Yuichiro Hayasaka³, Toyohiko J Konno^{1

3}

Affiliations

¹ Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
² Center for Advanced Materials, Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki 305-8687, Japan.
³ The Electron Microscopy Center, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.

PMID: 29016921
DOI: 10.1093/jmicro/dfx021

Abstract

We have examined the advanced application of transmission electron microscopy (TEM) for the structural characterization of a composite of cellulose nanofiber (CNF) and palladium (Pd) nanoparticles. In the present study, we focused on electron-irradiation damage and optimization of high-resolution TEM imaging of the composite. The investigation indicates that the CNF breaks even under low-electron-dose conditions at an acceleration voltage of 200 kV. We then applied lower-voltage TEM at 60 kV using a spherical aberration corrector and a monochromator, in order to reduce electron-irradiation damage and improve the spatial resolution. The TEM observation achieved high-resolution imaging and revealed the existence of small Pd nanoparticles, around 2 nm in diameter, supported on the CNF. It is considered that the use of a monochromator in combination with spherical aberration correction contributed to the atomic and nanoscale imaging of the composite, owing to the improvement of the information limit under a lower-acceleration voltage.

Keywords: Pd nanoparticles; cellulose nanofiber; information limit; lower-voltage high-resolution TEM; monochromator; spherical aberration corrector.