Synthesis of Layered MnO2 Nanosheets for Enhanced Oxygen Reduction Reaction Catalytic Activity

• The layered MnO2 nanosheets are used for oxygen reduction reaction.
• The MnO2 nanosheets exhibit a high catalytic activity for oxygen reduction.
• Oxygen reduction involves a coexisting pathways via 2- and 4-electron transfer.

In this study, a novel layered manganese oxide (MnO2) nanosheets was prepared by using a facile method with graphene oxide as the template, and its electrocatalytic performance was studied. The results of cyclic voltammograms (CV) and the rotating disk electrode (RDE) measurements show that the MnO2 nanosheets possess excellent electrocatalytic activity for oxygen reduction reaction (ORR) in alkaline medium. The electron transfer number of the nanosheets electrode was measured to be 3.4, which lied between the two-electron and four-electron processes, suggesting that the oxygen reduction on nanosheets might proceed by a coexisting pathway involving the two-electron and four-electron transfer.