Search

[Display omitted] • Co-Mo-based bimetallic oxide is constructed via a facile anodization method. • The as-prepared Co/CoO/Co 2 Mo 3 O 8 catalyst displays excellent HER performance. • The unique structure benefits the H* adsorption and promotes the reaction kinetics. • The recovered Co/CoO/Co 2 Mo 3 O 8 shows reproductive HER performance. 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/Co 2 Mo 3 O 8 shows enhanced HER performance compared with Co(OH) 2 /CoMoO 4 and CoO/CoMoO 4 , 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/Co 2 Mo 3 O 8 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. [ABSTRACT FROM AUTHOR]

• Mesoporous CoS x is self-grown on the Co film by a cheap anodization method. • CoS x is an active bifunctional electrocatalyst towards overall water splitting. • Amorphous CoS x shows a better electrochemical performance than crystallized phase. Electrocatalysts based on transition metal sulfides (TMSs) are drawing accelerating concerns in renewable energy research because of their intrinsically excellent activities towards both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). To date, considerable efforts are made to improve the performance of these catalysts, but ignoring the improper synthesis strategy would incur additional cost to the catalyst. Herein, a convenient, one-step anodization method is developed for fast construction of cobalt sulfides (CoS x). Without any high-temperature or long-time treatment, mesoporous CoS x is self-grown on the metal substrate in minutes. As a result, as-anodic CoS x requires overpotentials of 102 mV for HER and 284 mV for OER to achieve a current density of 10 mA m−2 in alkaline solution. Moreover, the tandem bifunctional as-anodic CoS x exhibits a required cell voltage of 1.64 V for overall water splitting in alkaline solution, exceeding most of the documented Co-based electrocatalysts. Mesoporous cobalt sulfides (CoS x) were self-grown on the metal substrate via a facile, one-step anodization method for high efficient overall water splitting. [Display omitted] [ABSTRACT FROM AUTHOR]