Enhancing bifunctional electrocatalysts of hollow Co3O4 nanorods with oxygen vacancies towards ORR and OER for Li–O2 batteries

•Oxygen vacancies play an important role to electrocatalytic activity.•Bifunctional electrocatalyst towards ORR and OER.•Bifunctional electrocatalyst for Li–O2 batteries.•Electronic bandgap depends on the oxygen vacancies controlling electrocatalytic activity. The Co3O4, which is on the top of volcano plot, having high oxygen vacancy of ca. 30% finely tuned promotes narrow band gap, resulting in the facilitation of the electron and charge transportation. The as-synthesized Co3O4 catalyst can improve the electrocatalytic activity towards oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). The as-prepared catalyst exhibits the superior ORR/OER stability for which the relative current decays only 7% and 14% for OER and ORR, respectively. By contrast, the OER stability of the RuO2 catalyst presents the significant decay in relative current about 20%. The ORR stability of Pt/C also remarkably decreases to 29%. The catalyst here can be used as an efficient bifunctional catalyst at the cathode of Li–O2 battery. It provides the superior performance as compared to that using the state-of-the-art Pt/C and RuO2/C electrocatalysts. [Display omitted]