Facet-controlled electrosynthesis of nanoparticles by combinatorial screening in scanning electrochemical cell
Heekwon Lee1, Jesús Alberto Muñoz-Castañeda1, Hang Ren1,2,3
1Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA. hren@utexas.edu.
Abstract:
Controlled synthesis of faceted nanoparticles on surfaces without explicit use of ligands has gained attention due to their promising applications in electrocatalysis and chemical sensing. Electrodeposition is a desirable method; however, precise control over their size, spatial distribution, and morphology requires extensive optimization. Here, we report the spatially resolved synthesis of shape-controlled Pt nanoparticles and fast screening of synthesis conditions in scanning electrochemical cell microscopy (SECCM) with pulse potentials. The screening is performed on isolated ∼μm2 areas in SECCM, enabling multiple experimental conditions to be evaluated in a single mapping experiment. The screening reveals that the formation of (100) facets in Pt nanoparticles is sensitive to the upper and lower potential limits of the square-wave potential pulse. The facet selectivity is attributed to a facet-dependent migration effect influenced by the concurrent hydrogen evolution reaction during Pt deposition. Moreover, the density and size of nanoparticles can be controlled. This approach offers a pathway toward automated synthesis and characterization of faceted metallic nanoparticles, providing opportunities for advancements in electrocatalysis and sensor development.
