Anodically designing of refreshable bi-metallic oxides for highly-efficient hydrogen evolution

Bi-metallic oxide based electrocatalysts exhibit great potential for the hydrogen evolution reaction (HER) on account of their abundant reserves, high stability and rich active reaction sites. Getting rid of complicate and time-/energy-consuming process of previous synthesis strategies, herein, we introduce an anodization technique for quickly constructing Co-Mo-based bimetallic oxides on Co foil. As a result, the as-prepared Co/CoO/Co2Mo3O8 shows enhanced HER performance compared with Co(OH)2/CoMoO4 and CoO/CoMoO4, which provides an overpotential of 78 mV at a current density of 10 mA cm−2 and a Tafel slop of 59 mV dec−1 in 1 M KOH. Additionally, the recovered Co/CoO/Co2Mo3O8 shows reproductive HER performance with an overpotential in the range of 70–90 mV, indicating the high efficiency and sustainability of the proposed anodization strategy. These findings provide a new and efficient route to construct high-stable bi-metallic or multi-metallic oxides for large-scale energy conversion application.