Synergistic electronic and morphological engineering of Pt/TiN NTs@3D-TC4 electrode for stable and efficient water electrolysis at high current densities

Efficient hydrogen evolution at high current densities requires simultaneous optimization of intrinsic reaction kinetics, multiphase mass transport, and electrode durability. Here, we constructed a binder-free Pt/TiN NTs@3D-TC4 electrode by integrating Pt nanoparticles and in situ-grown TiN nanotube arrays on a three-dimensional printed porous titanium-alloy scaffold. Its high performance arises from three mutually reinforcing effects. First, the work function mismatch between Pt and TiN drives electron transfer from TiN to Pt, producing electron-rich Pt sites and an interfacial built-in electric field. Combined with Pt–N coordination and d - p orbital hybridization, this electronic metal-support interaction optimizes hydrogen adsorption and desorption energetics, thereby enhancing intrinsic hydrogen evolution reaction activity. Second, the periodic macroporous scaffold and nanoparticle-assembled TiN nanotubes create a superhydrophilic and aerophobic multiscale transport network. This network promotes electrolyte infiltration, proton delivery, and rapid bubble detachment while mitigating gas shielding at high current densities. Third, robust Pt–N anchoring and binder-free integration of the catalytic layer with the conductive framework suppress Pt migration, aggregation, and detachment. Consequently, Pt/TiN NTs@3D-TC4 requires overpotentials of only 30.8 and 207 mV to deliver 10 and 1000 mA cm −2 , respectively. It also achieves a Pt mass activity of 20.81 A mg Pt −1 at 200 mV and operates stably for over 200 h at 1 A cm −2 . These results establish a practical electrode design that combines hierarchical transport regulation with interfacial electronic modulation for scalable hydrogen production at high current densities. Interfacial electron transfer optimizes H* adsorption/desorption; multiscale hydrophilic architecture accelerates bubble release and mass transport; Pt–TiN interaction ensures structural stability. The triple enhancement enables scalable, high-current-density water electrolysis. Download: Download high-res image (145KB) Download: Download full-size image