Pt nanoparticles decorated 3D printed hierarchical porous titanium alloy scaffolds for hydrogen evolution reactions at amper-level current densities

Most reported 3D electrodes currently lack a macroscopically ordered porous structure, hindering transport efficiency optimization and reducing the utilization of active materials and the surface area of the electrodes. In this study, a micro- and macroscopic hierarchical porous titanium alloy electrode modified with Pt nanoparticles (Pt/TNTs@3D-TC4) was created using electron beam melting (EBM) technology, anodic oxidation, and a water bath method. The micrometer-scale network structure enhanced electrolyte diffusion and bubble removal, whereas the surface nanostructures provided numerous anchoring sites for Pt nanoparticles. This unique micro- nano structure offers a large specific surface area and efficient mass transport, resulting in excellent acidic HER performance and stability at industrial current densities. X-ray photoelectron spectroscopy (XPS) and X-ray adsorption fine structure (XAFS) analyses confirmed an electronic metal-support interaction (EMSI) between Pt and TiO2 nanotubes (TNTs), with Pt nanoparticles anchored via Pt-O-Ti bonds. The electrode achieved the overpotential of 42 mV at-10 mA cm- 2, and 267 and 378 mV at-0.5 A cm- 2 and 1 A cm- 2, respectively. Exceptional stability was demonstrated, without significant deactivation after 120 h at 0.5 A cm- 2. This study offers a novel strategy in the industrial application of high-performance electrodes for electrochemical energy conversion.