Controlling the composition and nanostructure of Au@Ag–Pt core@multi-shell nanoparticles prepared by co-reduction method

• Published in: Materials today chemistry Vol. 38; p. 102132
• Main Authors: Lee, Hu-Jun, Hanyu, Daisuke, Dao, Anh Thi Ngoc, Kasai, Hitoshi, Suzuki, Minori, Yabu, Hiroshi, Nakatani, Hisayuki, Kaneko, Kenji
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: 3D tomography; Charge-transfer effect; Co-reduction; Multi-shell; Trimetallic nanoparticle; Charge-transfer effect; 3D tomography; Co-reduction; Trimetallic nanoparticle; Multi-shell
• ISSN: 2468-5194; 2468-5194
• DOI: 10.1016/j.mtchem.2024.102132

Three types of Au@Ag–Pt core@multi-shell nanoparticles (NPs) were synthesized via a co-reduction reaction from a galvanic replacement reaction (GRR) and a reducing agent, with different feeding ratios of Ag or Pt precursors. The morphology of the core-shell NPs showed a thin multi-shell with a mixture of Ag, void, and Pt granules, and their microstructure was investigated by scanning transmission electron microscopy. The effect of the Ag or Pt precursor feeding ratios on the competition of the two reduction reactions, and the subsequent impact on the nanostructure of Ag-void-Pt multi-shell were discussed. In the case of the sample with a reduced Ag precursor feeding ratio, the thickness of the Ag layer decreased significantly. The oxidation resistance of the Ag layer was improved due to the charge-transfer effect from Au to Ag, which suppressed galvanic replacement, and the reaction by the reducing agent was dominant. In the case of the sample with a reduced Pt precursor feeding ratio, the number of Pt granules was found to decrease while the volume of voids was maintained, suggesting that GRR was the dominant reaction in the co-reduction method. These results provide further insight into the co-reduction reaction mechanism and enable the control of noble trimetallic nanoparticles with complex shells. [Display omitted] •The influence of feeding ratios of Ag or Pt precursors was investigated for Au@Ag–Pt NPs synthesized by co-reduction method.•Microstructures of NPs were characterized by HAADF-STEM, EDS mapping, and 3D tomography.•The void regions within the shell part were visualized through 3D reconstruction images.•The feeding ratios of Ag and Pt precursors control the volume of voids and the amount of Pt granules, respectively.