Superaerophobic TiN Nanowires Boost Bubble Removal and Performance of Pt Catalysts for Highly Efficient Hydrogen Evolution

Electrocatalytic water splitting for green hydrogen production is often limited by bubble accumulation and sluggish interfacial processes, particularly under high current densities. To overcome these challenges, we design a conductive titanium nitride (TiN) nanowire array-supported platinum catalyst (TiN-Pt) for highly efficient hydrogen evolution reaction. The key innovation lies in the construction of vertically aligned TiN nanowires with engineered wettability, which optimizes the solid-liquid-gas three-phase interface, enhances electron transfer, and facilitates directional bubble transport. The TiN-Pt catalyst exhibits outstanding stability (>1,000 h) at 1 A cm^-2 in both acidic and alkaline media. The assembled proton exchange membrane (PEM) electrolyzer with TiN-Pt as the cathode delivers a current density of 1 A cm^-2 at 2.2 V with good durability. <i>In situ</i> imaging and electrochemical impedance spectroscopy confirm that the catalyst enables rapid bubble detachment, suppresses bubble-induced dead zones, and significantly improves the overall electrolysis efficiency.