Ion-Sieve-Confined Synthesis of Size-Tunable Ru for Electrochemical Hydrogen Evolution.

The controllable and low-cost synthesis of nanometal particles is highly desired in scientific and industrial research. Herein, size-tunable Ru nanoparticles were synthesized by using a novel ion-sieve-confined reduction method. The HTiO ion-sieve was used to adsorb Ru into the hydroxyl-enriched porous [TiO] layers. The confined environment of the interlayer space facilitates Ru-Ru collision and bonding during annealing, achieving a precise reduction from Ru to Ru without additional reductants. Owing to the confinement effect, Ru nanoparticles are uniformly embedded in the pores on the surface of the postannealed TiO matrix (Ru@TiO). Ru@TiO exhibited a lower overpotential than Pt/C (57 vs 87 mV at 10 mA cm) for the HER in 0.1 M KOH solution. The confinement-induced reduction of metal ions was also preliminarily proved in ion-exchanged zeolites, which provides facile and abundant approaches for the size-controllable synthesis of nanometal catalysts with high catalytic activity.