N, P, and S tri-doped holey carbon as an efficient electrocatalyst for oxygen reduction in whole pH range for fuel cell and zinc-air batteries

• Published in: Carbon (New York) Vol. 179; pp. 365 - 376
• Main Authors: Long, Yongde, Ye, Fenghui, Shi, Lei, Lin, Xuanni, Paul, Rajib, Liu, Dong, Hu, Chuangang
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.07.2021; Elsevier BV
• Subjects: Biochemical fuel cells; Carbon; Cathodes; Charge transfer; Electrocatalysis; Electrocatalysts; Electrolytes; Electrolytic cells; Fuel cells; Green energy devices; Mass transport; Metal air batteries; Metal-free carbon-based catalyst; Nanomaterials; Oxygen reduction reaction; Oxygen reduction reactions; pH-universal performance; Proton exchange membrane fuel cells; Structural hierarchy; Tri-doping; Zinc-oxygen batteries; Metal-free carbon-based catalyst; Tri-doping; Oxygen reduction reaction; pH-universal performance; Green energy devices
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2021.04.039

Although, metal-free electrocatalysts have been exhibiting attractive oxygen reduction reaction (ORR) performance comparable to Pt/C in alkaline electrolytes, their activity in acidic and neutral mediums is unsatisfactory, hindering their widespread application in energy devices, such as proton exchange membrane fuel cells (PEMFCs), neutral metal-air batteries, and biofuel cells. Herein, N,P,S tri-doped holey carbon (NPS-HC) nanomaterials have been prepared using a one-step method with large specific surface area (1656.0 m2 g−1), abundant holes and edges, and high heteroatom content (7.57 at.%). The optimized NPS-HC exhibits outstanding ORR performance in universal pH mediums, being closely comparable to the commercial Pt/C. The NPS-HC is also utilized as air cathode in alkaline (peak power density: 286.6 mW cm−2 @ 488.1 mA cm−2) and neutral (85.7 mW cm−2 @ 228.8 mA cm−2) electrolytic Zn-air batteries as well as the ORR cathode in a practical PEMFC (275.1 mW cm−2) with comparable or superior performances than the previous reports. Such excellent electrocatalytic performance is attributed to the N,P,S tri-doping induced synergistic charge transfer and spin redistribution along with the hierarchical holey structure with exposed active sites and facilitated mass transport. Thus, this earth-abundant carbon-based nanomaterial holds great potential for high-performance pH-universal ORR catalysis in various energy-related technologies. This article presents a metal-free carbon-based nanomaterial for outstanding ORR performance in universal pH mediums, and its utilization as the air cathode in alkaline and neutral Zn-air batteries as well as the ORR cathode in a practical PEM fuel cell for efficient energy storage and conversion. [Display omitted] •N,P,S tri-doped holey carbon (NPS-HC) is prepared through a one-step method.•NPS-HC has a unique structure with a large specific surface area and abundant holes.•NPS-HC exhibits an outstanding ORR performance in pH-universal mediums.•NPS-HC shows good performance in alkaline/neutral Zn-air batteries and fuel cells.