One-step, in situ formation of WN-W2C heterojunctions implanted on N doped carbon nanorods as efficient oxygen reduction catalyst for metal-air battery
Yue Du, Wenxue Chen, Lina Zhou, Rui Hu, Shizhu Wang, Xueqing Li, Yunlong Xie, Lun Yang, Yisi Liu, Zhenhui Liu
Abstract
Transition metal nitrides and carbides have attracted intensive attentions in metal-air battery application due to their metallic electron transport behavior and high chemical stability toward the oxygen reduction reaction (ORR). Herein, the polyoxometalate@polyaniline composite derived WN-W 2 C heterostructured composite (WN-W 2 C@pDC) has been fabricated through an in situ nitriding-carbonization strategy, with WN-W 2 C nanoparticles implanted on N doped carbon nanorods. As-fabricated WN-W 2 C@pDC demonstrates prominent electrocatalytic performance towards ORR and excellent cycling stability in metal-air battery, which possesses positive half-wave potential and large diffusion limiting current density (0.81 V and 5.8 mA·cm −2 ). Moreover, it demonstrates high peak power density of 157.4 mW·cm −2 as Al-air primary cathode and excellent stability at the discharge—charge test (> 500 h) of Zn-air secondary battery. The excellent activity and durability of WN-W 2 C@pDC catalyst should be attributed to the combined effect of intimate WN-W 2 C heterointerfaces, unique embedded nanoparticles structure, and excellent electrical media of N doped carbon, confirmed by a series of contrast experiments.