Diverse Hierarchical Meso/Nanoporous Pt Film Electrocatalysts Prepared via Hydrogen Adsorption-Assisted Dynamic Soft Templating

Abstract

In this study, we present an innovative approach for creating hierarchical meso/nanoporous Pt films using dynamic soft templating. The fabrication process, called dynamic soft templating, involves Pt electrodeposition within a specialized bicontinuous microemulsion (BME) system characterized by a sophisticated three-dimensional network comprising water and oil phases, surfactants, and cosurfactants. Pt electrodeposition exclusively occurs in the water phase of the BME. This results in a porous Pt film exhibiting a nanostructure mirroring the oil solution/water solution nanostructure (solution/solution structure) of the BME, the size of which can be tailored by adjusting the BME composition. Through a simultaneous interplay of Pt electrodeposition and overpotential deposition of hydrogen (H-OPD, dissociative adsorption of water), potential-dependent Pt mesostructures are dynamically shaped. As a result, we achieve diverse morphologies in the form of hierarchical meso/nanoporous Pt films. The potential applications of the films are evaluated as electrocatalysts for the methanol oxidation reaction (MOR), and it was found that the electrocatalytic performances seem to be sensitive to nanoporosity and not relevant to mesoporosity.