Ruthenium Cluster Decorated Titanium Dioxide Nanowire Arrays for Alkaline Hydrogen Evolution

Enhancing the performance of ruthenium (Ru)-based electrocatalysts for the alkaline hydrogen evolution reaction (HER) presents a significant challenge. Herein, titanium dioxide nanowire arrays decorated with ruthenium clusters were grown on carbon cloth (Ru-TiO₂ NWAs/CC) via a two-step hydrothermal method. The nanowire array structure increases the surface area of the substrate, allowing for more Ru clusters to be decorated, thereby improving catalytic activity. The resulting Ru₃–TiO₂ NWAs/CC catalyst exhibits prominent HER performance in 1.0 M KOH with overpotentials of 61 at 10 mA cm⁻² and a Tafel slope of only 47.4 mV dec⁻¹. Furthermore, it maintains outstanding stability under alkaline conditions for more than 10 h. The Ru clusters decoration enhances the TiO₂/CC kinetic, more active sites were exposed on nanowires of the surface and accelerated electron transport, thus reducing the charge transfer barrier. After the electrochemical test, the morphology and structure of Ru₃–TiO₂/CC remained largely unchanged, and the valence states of the elements remained stable. This work paves the road to exploiting highly active and cost-efficient electrocatalysts for alkaline hydrogen evolution.