(167g) Synthesis of Bimetallic Alloy Nanoparticles through the Visible-Light Mediated Reduction of a Bimetallic Oxide Precursor: Case Study of Ag-Pt Nanoparticle Synthesis

Bimetallic nanoparticles are known to exhibit chemical and physical properties unique from their individual components. However, the synthesis of well-mixed alloy nanoparticles is often limited to highly miscible metals. This limitation has previously been overcome by using extreme synthesis conditions such as gamma radiation or high temperature reduction to kinetically trap the atoms of each metal in a single nanostructure.^1,2 In this presentation, we demonstrate a more facile synthesis approach for creating well-mixed bimetallic alloy nanoparticles of immiscible metals. We synthesize Ag-Pt nanoparticles through the visible light-induced reduction of a hollow bimetallic oxide precursor composed of Ag and Pt oxide. We show that Pt atoms are initially concentrated near the surface of the hollow precursor. The low-temperature reduction of the oxide causes the hollow precursor to become unstable and collapse into well-mixed alloy nanoparticles. We discuss the physical processes that lead to the light-mediated reduction of the oxide precursor and the wider applicability of synthesizing alloy nanoparticles composed of immiscible metals through the use of bimetallic precursors.³

1. Zhang, Z., Nenoff, T. M., Huang, J. Y., Berry, D. T. & Provencio, P. P. Room Temperature Synthesis of Thermally Immiscible Ag−Ni Nanoalloys. J. Phys. Chem. C 113, 1155–1159 (2009).

2. Holewinski, A., Idrobo, J.-C. & Linic, S. High-performance Ag–Co alloy catalysts for electrochemical oxygen reduction. Nat. Chem. 6, 828–834 (2014).

3. Aslam, U. & Linic, S. Kinetic Trapping of Immiscible Metal Atoms into Bimetallic Nanoparticles through Plasmonic Visible Light-Mediated Reduction of a Bimetallic Oxide Precursor: Case Study of Ag–Pt Nanoparticle Synthesis. Chem. Mater. 28, 8289–8295 (2016).