Mixed‐Phase TiO ₂ Nanotubes Enhance Ru Nanoparticle Activity for Hydrogen Evolution in pH‐Neutral Electrolytes

Bromide‐mediated decoupled water electrolysis provides a disruptive strategy to overcome the limitations of conventional water electrolysis, operating effectively in a pH‐neutral NaBr electrolyte. To advance the viability of this approach, it is crucial to minimize both the reliance on platinum‐group metal catalysts and the associated cathodic polarization loss. This work demonstrates a “job‐sharing” effect between mixed‐phase TiO 2 nanotube supports and Ru nanoparticles (NPs), achieving efficient hydrogen evolution in cost‐effective Ti‐based cathodes with ultralow Ru loading (≈4 μg cm −2 ). This cooperative effect substantially improves the specific activity of the Ru catalyst, delivering electrode performance superior to that of Ru NPs on carbon supports. Long‐term electrolysis tests confirm stable performance for more than 125 h without observable electrode degradation. This approach advances the prospect of efficient water electrolysis in pH‐neutral electrolytes.