Nitrogen and Phosphorus-codoped Carbon Nanotube/Fe 2 P Nanoparticle Hybrids Toward Efficient Oxygen Reduction and Zinc-air Batteries

• Published in: Journal of the Electrochemical Society 2022-06, Vol.169 (6), p.66509
• Main Authors: Wang, Ruixiang, Yuan, Yuanliang, Zhong, Xiaocong, Zhu, Yirui, Liu, Jiaming, Xie, Yongmin, Zhong, Shuiping, Xu, Zhifeng
• Format: Article
• Language: English
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/ac766a

Incorporating metal compound nanoparticles in carbonaceous matrix is a valid strategy to fabricate highly efficient oxygen reduction electrocatalysts. Herein, N, P-codoped carbon nanotubes embedded with Fe 2 P nanoparticles (Fe 2 P/NPCt) were synthesized in this work. Results show carbon nanotubes have a large specific surface area (987 m 2 g −1 ) with an inner diameter of ∼60 nm. About 5.90 wt% nitrogen (35.18% pyridinic N) and 2.56 wt% phosphorus (mainly in the form of P–C and P–Fe) was doped in Fe 2 P/NPCt. HRTEM and XRD results confirmed the well dispersed Fe 2 P nanoparticles in 5 ∼10 nm on carbon nanotubes. The electrochemical performance of Fe 2 P/NPCt was evaluated in 0.10 M KOH using cyclic voltammetry, linear scanning voltammetry, and chronoamperometry. Fe 2 P/NPCt exhibits high electrocatalytic activity towards oxygen reduction with an onset potential of 1.029 V (vs RHE) and a limited current density of 6.79 mA cm −2 , surpassing those of 20% Pt/C (0.950 V and 5.20 mA cm −2 ). Furthermore, Fe 2 P/NPCt presents outstanding durability and good methanol tolerance during long-term ORR. When assembled in a primary zinc-air battery (ZAB), the maximum power density and specific capacity of ZAB reach 175.48 mW cm −2 and 744.1 mAh g −1 , respectively, outperforming ZAB equipped with 20% Pt/C.