Green Synthesis of Catalytic 3D Platinum Nanostructures from a Body-Centered Cubic Pluronic Micellar Array Template

Abstract

Ordered and well-interconnected 3D electrode nanostructures open up exciting perspectives in catalysis, sensing and energy harvesting. Here, highly ordered 3D nano-sized Pt mesoporous structures based on the I-Wrapped Package (I-WP) architecture with 13.5 nm unit cell size, previously unreported for metal nanomaterials, are presented. The samples are synthetized by soft-template electrodeposition, using the body-centred cubic (BCC) lyotropic crystalline micellar phase of Pluronic F68 as the template. The specific surface area of the resulting Pt nanoarchitecture is 36 ± 13 m² g⁻¹. The oxygen reduction reaction kinetic current is 0.98 mA cm⁻²; the current density normalized by the electrochemical active surface area and the weight of deposited Pt are 0.92 mA cm⁻² and 153.53 A g⁻¹, respectively, showing superior properties than conventional Pt nanostructures produced by surfactant templates. These results suggest a nanostructure based on the topology of the I-WP minimal surface, representing the first case at this length scale from a metallic material, opening up new research directions in fundamental physics based on predicted thermal and phononic properties for this topology. The water-based template provides a chemical-free, eco-friendly route for ordered mesoporous conductive nanomaterials manufacturing, inspiring future trends in the field.