Size-Dependent Threshold of the Laser-Induced Phase Transition of Colloidally Dispersed Copper Oxide Nanoparticles

authored by

Daniel Kranz, Patrick Bessel, Max Niemeyer, Hadir Borg, Marina Rosebrock, Rasmus Himstedt, Nadja C. Bigall, Dirk Dorfs

Abstract

Due to their unique optical properties, nanoparticles are well suited for heating by laser irradiation. In this context, colloidally dispersed particles are of particular interest because in conventional ways of heating, the maximum attainable temperature is limited by the boiling point of the solvent. With the right choice of the used laser wavelength, it is possible to selectively heat these particles above the melting point of the material whereas the surrounding and laser-transparent medium remains comparatively cold. This type of laser process is called laser melting in liquids (LML). To further investigate the possibilities of laser-induced heating processes, colloidally dispersed copper(II) oxide (CuO) nanoparticles were synthesized, dispersed in ethanol, and irradiated with a nanosecond-pulsed Nd:YAG laser. In this way, a laser-induced phase transition into the copper richer copper(I) oxide (Cu2O) phase and into elemental copper can be observed. The conversion process is followed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction (SAED), and UV-vis spectroscopy. It is shown that in the initial LML process a minimum particle size of 23-29 nm is required for a successful phase transition likely due to the size dependent heating efficiency, cooling effects, and the formation of nanobubbles.

Organisation(s)

Hannover School for Nanotechnology
Section Colloid Chemistry of Metals and Semiconductors, Spectroscopic Effects
Institute of Physical Chemistry and Electrochemistry
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
Section Catalysis and Membranes

Type

Article

Journal

The Journal of Physical Chemistry C

Volume

126

Pages

15263–15273

No. of pages

11

Publication date

15.09.2022

Publication status

Published

Peer reviewed

Yes

Electronic version(s)

https://doi.org/10.1021/acs.jpcc.2c03815 (Access: Closed)