Precision Electrosynthesis of Heterostructured Bimetallic Nanoparticles by Scanning Electrochemical Cell Microscopy

<br/><b>ABSTRACT</b><br/>Heterostructured bimetallic nanoparticles, such as core-shell and multishell configurations, exhibit unique properties that surpass those of their monometallic counterparts. However, the complexity of their synthesis in controlling size, structure, and composition underscores the need for high-throughput techniques to accelerate materials discovery. This presentation introduces a method for the serial electrosynthesis of bimetallic nanoparticles with precise compositional and structural control within individual particles. This approach utilizes a dual-channel nanopipette within a scanning electrochemical cell microscopy (SECCM) framework, where a voltage bias between the channels regulates the local electrolyte environment. [1, 2] This localized nanofluidic control enables the sequential deposition of metal precursors (Pt-Cu and Pt-Ni in this work), facilitating the precise construction of core-shell and multishell nanoparticle structures. By controlling the electrodeposition rate through designated reduction potentials and deposition times, precise control over shell thickness and layer order is achieved. Synthesized nanoparticles are characterized using SECCM for electrocatalytic activity (e.g., hydrogen evolution reaction) and dark-field microscopy for optical properties, demonstrating the systematic fabrication of core-shell bimetallic nanoparticles. This methodology paves the way for automated synthesis and screening systems that can accelerate material discovery in electrocatalysis.<br/><br/><b>REFERENCES</b><br/>1. Lee, H., Matthews, K. C., Zhan, X., Warner, J. H., Ren H., Precision Synthesis of Bimetallic Nanoparticles via Nanofluidics in Nanopipets, <i>ACS Nano</i> <b>2023</b>, 17, 22, 22499–22507<br/>2. Wenzel S. F., Lee H., Ren H., Controlling Droplet Cell Environment in Scanning Electrochemical Cell Microscopy (SECCM) via Migration and Electroosmotic Flow, <i>Faraday Discuss.</i> <b>2024</b>, DOI:10.1039/D4FD00080C