Mo-doped SrCo0.5Fe0.5O3-δ perovskite oxides as bifunctional electrocatalysts for highly efficient overall water splitting

•Mo is successfully doped into SrCo0.5Fe0.5O3-δ perovskite oxides using a modified sol-gel method.•SrCo0.5Fe0.4Mo0.1O3-δ requires ∼200 and ∼310 mV overpotentials to reach 10 mA cm−2 for HER and OER.•A current density of 10 mA cm−2 could be achieved by applying a potential of 1.68 V vs. RHE in the SCFM10||SCFM10 electrolyzer.•SrCo0.5Fe0.4Mo0.1O3-δ exhibits remarkable stability for HER and OER in alkaline electrolyte. Perovskite oxides with high electrocatalytic activities and cost-effectiveness can be developed by rational doping. Here, we fabricate a series of perovskite oxides comprising SrCo0.5Fe0.5-xMoxO3-δ (x = 0, 0.05, 0.10, 0.15) doped with different proportions of Fe and Mo elements to enhance the long-term stabilities and electrocatalytic activities for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Among them, SrCo0.5Fe0.4Mo0.1O3-δ (SCFM10) exhibits the optimum electrocatalytic activity for water splitting, exhibiting overpotentials at −10 mA cm−2 and 10 mA cm−2 of ∼200 mV for HER and ∼310 mV for OER, respectively, generating a current density of 10 mA cm−2 using only 1.68 V in a two-electrode electrolytic cell. Additionally, SCFM10 demonstrates outstanding stability, maintaining continuous operation for 100 h without visible decay. These results give some new points of view into the development of bifunctional catalysts for the purpose of efficient water splitting in a sensible way. [Display omitted]