Direct Observation of Hollow Bimetallic Nanoparticle Formation through Galvanic Replacement and Etching Reactions

Wenhui Wang; Ivan Erofeev; Ya He; Fangqi Yang; Hongwei Yan; Jiong Lu; Utkur Mirsaidov

doi:10.1021/acs.nanolett.3c02575

Direct Observation of Hollow Bimetallic Nanoparticle Formation through Galvanic Replacement and Etching Reactions

Nano Lett. 2023 Dec 13;23(23):10725-10730. doi: 10.1021/acs.nanolett.3c02575. Epub 2023 Nov 21.

Authors

Wenhui Wang^{1

2}, Ivan Erofeev^{1

2}, Ya He^{1

2}, Fangqi Yang³, Hongwei Yan^{1

2}, Jiong Lu³, Utkur Mirsaidov^{1

2

4

5}

Affiliations

¹ Department of Physics, National University of Singapore, 117551, Singapore.
² Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, 117557, Singapore.
³ Department of Chemistry, National University of Singapore, 117543, Singapore.
⁴ Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 117546, Singapore.
⁵ Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore.

PMID: 37988597
DOI: 10.1021/acs.nanolett.3c02575

Abstract

Hollow bimetallic nanoparticles (NPs) formed from metal oxide NP templates are widely used catalysts for hydrogen evolution and CO₂ reduction reactions. Despite their importance in catalysis, the details of how these NPs form on the NP templates remain unclear. Here, using in situ liquid-phase transmission electron microscopy (TEM) imaging, we describe the conversion of Cu₂O template NPs to hollow PdCu NPs. Our observations show that a polycrystalline PdCu shell forms on the surface of the template via a galvanic replacement reaction while the template undergoes anisotropic etching. This study provides important insights into the synthesis of hollow metallic nanostructures from metal oxide templates.

Keywords: Metal oxide; bimetallic; hollow nanoparticles; in situ TEM; liquid cell.