Non-equilibrium synthesis of stacking faults-abundant Ru nanoparticles towards electrocatalytic water splitting

Metallic nanomaterials with multidimensional defects are promising for electrocatalysis, whereas exploring facile approaches to synthesize such materials with peculiar structure remains challenging. Here, we firstly synthesized Ru nanoparticles with abundant stacking faults (SFs) combining ultrafast heating with rapid quenching. The close-packed planes of perfect hexagonal closed-packed partially transform into face-centered cubic in the SFs region. It requires 196 mV and 35 mV to drive hydrogen evolution reaction and oxygen evolution reaction under 10 mA/cm2 current density, prominently expedites overall water splitting with 1.51 V in acid. Theoretical calculations demonstrate the performance is originated from synergistic effect of the SFs and induced continuous strain field, among which the dominant compressive strain attenuates crystal field splitting effect of Ru sites, thus enhancing the electron transfer of Ru sites. The excellent inter-orbital p-d transfers determine strong electronic activities for boosting OER performance. This work provides insights for rational design of catalysts with defective structures. [Display omitted] •SF-Ru NPs were prepared by a non-equilibrium ultrafast synthesis strategy (sub 1 s).•It requires 196 and 35 mV to reach current density of 10 mA/cm2 for OER and HER.•Compressive strain dominated field adjusts the center of d-band to optimal position.•Synergistic effect between stacking faults and strain field leads to the performance.