Interface and morphology engineering of Ru-FeCoP hollow nanocages as alkaline electrocatalyst for overall water splitting.

Interface and Morphology engineering strategies of electrocatalysts are of great importance to promote water splitting performance, although still facing many challenges. In this work, we present a facile method for preparing Ru-anchored hollow FeCoP nanocages electrocatalyst with ultrathin sheets. The hollow structure composed of ultrathin nanosheets and rich heterogeneous interfaces benefit the as-synthesized catalyst to exhibit small overpotentials of 310 mV and 94 mV at the current density of 10 mA·cm⁻² for oxygen evolution reaction and hydrogen evolution reaction, respectively. When Ru-FeCoP nanocages were employed as the bifunctional catalyst for overall water splitting, the potential of 1.65 V was obtained to reach the current density of 10 mA·cm⁻². The experimental results confirmed that the formation of hierarchical hollow structure facilitated the exposure of active sites and enhanced the electrocatalytic activity. Meanwhile, XPS and DFT data also reveal that the presence of heterogeneous interfaces changed the electronic structure, optimized the absorption of the intermediates, significantly reduced the energy barrier of water dissociation and promoted the release of H 2. This work offers an effective route for rational design of low-loading noble metal-anchored metal phosphide with the hierarchical hollow structure and rich interfaces towards overall water splitting. [Display omitted] • A novel Ru-anchored FeCoP hierarchical hollow nanocages with ultrathin nanosheets was designed and synthesized. • Ru-FeCoP nanocages demonstrated improved bifunctional catalytic activity and exceptional cycling stability for both oxygen evolution reaction and hydrogen evolution reaction in alkaline. • The strong interaction between Ru nanoparticles and FeCoP nanosheets optimizes the electronic structure and the adsorption of the intermediates. • The construction of the interface reduces the energy barrier of water dissociation and promotes electrocatalytic activity. [ABSTRACT FROM AUTHOR]