查找使用阿拉丁产品的科研文献

Preparation of N-doped nano-hollow capsule carbon nanocage as ORR catalyst in alkaline solution by PVP modified F127

Zhongyu Qiu,Naibao Huang,Xiaowen Ge,Jiaping Xuan,Pei Wang

In order to reduce the cost of oxygen reduction reaction (ORR) catalyst, a metal-free N-doped carbon nanocage as ORR catalysts is prepared by using Polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) three-block copolymer (F127), polyvinyl pyrrolidone (PVP) and Zn (OH) 2 as a carbon source, nitrogen source and the morphology retaining agent, respectively, via a self-template method. The structure and microstructure of the N-doped carbon nanocage are characterized via physical characterization methods such as X-ray diffraction, Raman spectroscopy , scanning electron microscopy, transmission electron microscopy , Brunauer–Emmett–Teller method, and X-ray photoelectron spectroscopy. Electrochemical properties are evaluated in an O 2 -saturated alkaline solution. The obtained sample pyrolyzed at 800 °C with 10% content of PVP (C–N-800) presents nano-hollow carbon capsule with a diameter of 100 nm and shell thickness of 8 nm, and has the maximum surface area of 978 m 2 ·g −1 . In O 2 -saturated 0.1 M KOH solution, C–N-800's onset potential, limit current density, and half-wave potential, which are 0.87 V, 5.73 mA/cm 2 @0.45 V, and 0.77 V, respectively, are close to those of commercial 20% Pt/C catalysts. Meanwhile, its electrochemical performance only loss 11.75% after 5000 cycles, showing excellent ORR catalytic performance and stability. During self-assembly of F127, the added PVP participated into the process. Pyrolysis at 800 °C would result in the complete decomposition of F127 and PVP's lipophilic. So, the metal-free N-doped carbon nanocage was obtained and behaved excellent ORR catalytic activity and stability.