In this paper, nano Ag4Bi2O5/rGO composite catalyst was obtained by in-situ growth and co-precipitation. The nano Ag4Bi2O5 with a length of 200–300 nm and a width of 10–20 nm is supported by the surface of reduced graphene oxide. The obtained catalyst was represented by SEM, XRD, XPS, EDS and TG-DTG methods, and its electrocatalytic properties were evaluated by RDE, linear sweep voltammetry, EIS and cyclic voltammetry tests. The CV results display that there is a significant oxygen reduction peak current (2.27 mA cm−2) at the potential of 0.82V in the oxygen saturated 0.1 mol L−1 KOH electrolyte. The LSV result shows, the catalyst has slightly higher current density (4.96 mA cm−2) and half-wave potential (0.75 V) than commercial Pt/C through a 4 electrons oxygen reduction mechanism. The results of i-t chronoamperometric method show the catalyst has superior methanol tolerance ability to the commercialized Pt/C (20%). Furthermore, the assembled Zn-O2 batteries with Ag4Bi2O5/rGO oxygen electrode provide better durability performance than commercialized Pt/C (20%) in the same alkaline electrolyte.

Ag 4 Bi 2 O 5 /MnO 2 nano-sized material was synthesized by a co-precipitation method in concentrated KOH solution. The morphology characterization indicates that MnO 2 nanoparticles with a size of 20 nm are precipitated on the surface of nano Ag 4 Bi 2 O 5 , forming a structure like corn on the cob. The obtained material with 60% Mn offers slightly higher initial potential (0.098 V vs. Hg/HgO) and limiting current density (−5.67 mA cm −2 ) at a rotating speed of 1600 rpm compared to commercial Pt/C (−0.047 V and −5.35 mA cm −2 , respectively). Furthermore, the obtained material exhibits superior long-term durability and stronger methanol tolerance than commercial Pt/C. The remarkable features suggest that the Ag 4 Bi 2 O 5 /MnO 2 nano-material is a very promising oxygen reduction reaction catalyst.

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