Magnetron Sputtering Deposition Cu@Onion-like N–C as High-Performance Electrocatalysts for Oxygen Reduction Reaction

• Published in: ACS applied materials & interfaces 2017-12, Vol.9 (48), p.41945-41954
• Main Authors: Shao, Hongyang, Zhang, Xiaoming, Huang, Hao, Zhang, Kan, Wang, Menglong, Zhang, Cai, Yang, Yifan, Wen, Mao, Zheng, Weitao
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.7b16682

The idea of a core–shell structure can promote the utilization of nonprecious metallic catalysts by enhancing their activity and stability for the oxygen reduction reaction (ORR). Developing a low-cost, high-efficiency, and high-reproducibility method for synthesizing core–shell-structured materials represents an urgent challenge. Here, we fabricate encapsulated Cu nanoparticles with nitrogen-doped onion-like graphite nanoshells (Cu@onion-like N–C) as an efficient ORR catalyst by magnetron sputtering, in which the graphite shells grow by an in situ self-assembly process activated by the surface-catalyzed behavior with Cu nanoparticles. The results show that the CuCN-650 °C catalyst achieves the optimized Cu@onion-like N–C structure with small-sized Cu nanoparticles and a few-layer nanoshells and exhibits excellent ORR electrocatalytic properties, including a half-wave potential and onset potential similar to those of commercial Pt/C, coupled with better stability and higher methanol tolerance than for commercial Pt/C in alkaline electrolytes. The internal Cu nanoparticles in the core–shell structure not only promote the formation of a high content of pyridinic N but also donate the electronic charges to outer N-doped C shells, and thus the synergistic effect between the encapsulated Cu nanoparticles and N-doped C shells is responsible for the excellent electrocatalytic activity for the ORR.