Enhanced oxygen reduction activity ofα-MnO₂by NH₃plasma treatment

Oxygen vacancies and heteroatom doping play important role in oxygen reduction activity of metal oxides. Developing efficient modification method is one of the key issues in catalysts research. Room temperature plasma treatment, with the advantages of mild working conditions, no emissions and high efficiency, is a new catalyst modification method developed in recent years. In this work, hydrothermal synthesizedα-MnO₂nanorods are treated in NH₃plasma at room temperature. In the reducing atmosphere, oxygen vacancies and N doping are achieved simultaneously on the surface. The NH₃plasma etched MnO₂demonstrate a significant enhanced oxygen reduction activity with half-wave potential of 0.84 V, limiting current density of 6.32 mA cm^-2and transferred electrons number of 3.9. The Mg-air battery with N-MnO₂display a maximum power density of 76.3 mW cm^-2as well as stable discharge performance. This work provides new ideas for preparing efficient and cost-effective method to boost the catalysts activity.