Search

A potential non-noble metal oxide catalyst with its low-cost and efficient catalytic ability attract increasing attention. In this paper, a highly efficient bifunctional electrocatalyst Co||MnCo 2 O 4.5 /NC with heterostructure and oxygen vacancies is prepared utilizing solid reaction in-situ. The optimal catalyst is obtained at 650 °C with the mass ratio (1:8) of MnCo 2 O 4.5 and Dicyandiamide (DCD). It shows excellent electrocatalytic activity for oxygen reduction reaction (ORR) with high half-wave potential (0.81 V) and limit current density (6.22 mA cm−2), which is better than that of the commercial 20% Pt/C(0.81 V, 5.52 mA cm−2). At the same time, it also exhibits superior electrocatalytic activity for oxygen evolution reaction (OER) with low overpotential (330 mV) and a faster dynamics process. The superior electrocatalytic properties may be resulted from the presence of heterostructure and increasing ratio of oxygen vacancies, which helps to the rapid transfer of electrons and creates more active sites. Moreover, the self-generated N-doped carbon provides high conductivity of the as-prepared Co||MnCo 2 O 4.5 /NC composite. It can be seen that the application of interface engineering technologies is useful for improving the performance of the catalyst, providing an effective and facile synthesis strategy for non-noble metal catalyst. • The Co||MnCo 2 O 4.5 /NC was prepared based on spinel MnCo 2 O 4.5 using solid phase reaction in situ. • The Co||MnCo 2 O 4.5 /NC has the dual characteristic of the heterostructure and more oxygen vacancies. • The Co||MnCo 2 O 4.5 /NC presents excellent difunctional electrocatalytic properties toward ORR and OER. • The zinc-air battery using Co||MnCo 2 O 4.5 /NC as a catalyst shows outstanding energy density and extraordinary stability. [ABSTRACT FROM AUTHOR]