Poplar‐Catkin‐Derived N, P Co‐doped Carbon Microtubes as Efficient Oxygen Electrocatalysts for Zn‐Air Batteries

Abstract

Abstract In this study, poplar‐catkin‐derived N, P co‐doped carbon microtube catalysts with highly active sites and a large accessible surface area exhibit desirable oxygen reduction reaction (ORR) activity in an alkaline solution and excellent applications in Zn‐air batteries (ZABs). In particular, the catalytic activity of the N, P co‐doped carbon microtubes toward the ORR is as good as that of benchmark Pt/C, albeit better in terms of tolerance and stability. Furthermore, a ZAB fabricated using the as‐developed catalyst exhibits a specific capacity of 649 mAh g Zn −1 and a peak power density of 125 mW cm −2 ; these values are comparable to those of Pt/C catalysts (644 mAh g Zn −1 and 130 mW cm −2 , respectively), indicative of the promising applications for sustainable energy storage. In addition, an alkaline water‐splitting cell powered by this assembled ZAB can generate H 2 gas in a stable manner under ambient conditions. The successful conversion of considerable catkin sources to high‐value carbon materials will provide insights into the future development of other high‐performance electrocatalysts from abundant “green” bio‐waste.