Carbon nanotube encapsulated in nitrogen and phosphorus co-doped carbon as a bifunctional electrocatalyst for oxygen reduction and evolution reactions

• Published in: Carbon (New York) Vol. 139; pp. 156 - 163
• Main Authors: Li, Jin-Cheng, Hou, Peng-Xiang, Cheng, Min, Liu, Chang, Cheng, Hui-Ming, Shao, Minhua
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.11.2018; Elsevier BV
• Subjects: active sites; batteries; Carbon; carbon nanotubes; Catalysis; catalysts; Catalytic activity; Chemical evolution; Chemical reactions; Doping; durability; Electrocatalysis; Electrocatalysts; Fuel cells; Metal air batteries; Nanotubes; Nitrogen; Nitrogen and phosphorus co-doped carbon; Noble metals; Oxygen; Oxygen evolution; oxygen production; Oxygen reduction; phosphorus; Rechargeable batteries; Rechargeable metal-air batteries; Reduction; Regenerative fuel cells; Single wall carbon nanotubes; Zinc-oxygen batteries; Oxygen evolution; Oxygen reduction; Nitrogen and phosphorus co-doped carbon; Fuel cells; Rechargeable metal-air batteries
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2018.06.023

The development of inexpensive and robust bifunctional reversible oxygen electrocatalysts is critical to rechargeable metal-air batteries and regenerative fuel cells. Here we reported a single-wall carbon nanotube (SWCNT) conductive network embedded in porous N, P co-doped carbon (SWCNT@NPC) as a bifunctional oxygen electrocatalyst. The SWCNT@NPC material showed excellent electrocatalytic activity with an oxygen reduction half-wave potential of 0.85 V and oxygen evolution potential of 1.678 V at 10 mA cm−2. When used to assemble rechargeable Zn-air batteries, SWCNT@NPC exhibited better catalytic activity as well as durability compared to commercial noble-metal catalysts. In particular, it is demonstrated that mutual promotion between N and P doping induces ultrahigh ORR activity while N doping is identified as the primary active sites for the OER. Mutual promotion between N doping and P doping induces high activity for oxygen reduction reaction while N doping is identified as the primary active sites for oxygen evolution reaction, which endow N, P co-doped carbons with excellent oxygen electrode catalytic performance. [Display omitted]