Synergistic effect between Ru cluster and Co3O4 nanowires assisted by B-O bonding for hydrogen evolution

Abstract

Anchoring noble metal nanoclusters (NCs) on appropriate supports through structural engineering is an effective strategy for reducing the noble metal loading and improving catalytic activity for alkali hydrogen evolution reaction (HER). Generally, the local coordination environment of the active sites is key factor to regulate the interaction between the metal atoms and support. Here, a simple boronation method is proposed for preparing ruthenium nanoclusters anchored on B-doped Co3O4 nanowires supported on Ni foam (denoted as Ru/B-Co3O4) for alkaline HER. B embedded into Co3O4 nanoarrays through B-O bonding can change the electronic structure between Ru active sites and Co3O4. After optimizing electronic structure of Ru and Co sites, Ru/B-Co3O4 showed remarkable activity for HER, with current density of 100 and 500 mA cm−2 at overpotential of 143 and 233 mV, respectively. The experimental and theoretical studies display that the embedding of B into Co3O4 effectively induces the electron transfer from Co to Ru atoms by bridging O atom, leading to the formation of electron-deficient Co sites. The charge redistribution of Ru accelerates the cleavage of H-OH, which optimizes H* adsorption energy and finally promotes HER. This study provides further insight into the regulation of metal-support interaction for HER electrocatalysts.