Details

Autor(en) / Beteiligte

• Zhong, Xing
• Jiang, Yu
• Chen, Xianlang
• Wang, Lei
• Zhuang, Guilin
• Li, Xiaonian
• Wang, Jian-guo

Titel

Integrating cobalt phosphide and cobalt nitride-embedded nitrogen-rich nanocarbons: high-performance bifunctional electrocatalysts for oxygen reduction and evolution

Ist Teil von

• Journal of materials chemistry. A, Materials for energy and sustainability, 2016-01, Vol.4 (27), p.10575-10584

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The demand for cost-effective bifunctional oxygen electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) for application in rechargeable metal-air batteries and fuel cells operated in alkaline solutions has increased over the decades. We report for the first time an easy procedure for a unique nitrogen-rich sandwich-architectured catalyst (CoNP[at]NC/NG) as a highly efficient bifunctional electrocatalyst for ORR and OER. Physical characterizations confirmed the coexistence of Co sub(2)P and Co sub(x)N crystal phases in the nanostructure. The as-prepared CoNP[at]NC/NG exhibited potent bifunctional electrochemical performance with superior positive onset potential, large kinetic current density, and outstanding stability toward both ORR and OER, thereby showing excellent activities compared with Pt/C and state-of-the-art nonprecious catalysts. The excellent performance could have originated from the robust conjugation between the Co sub(2)P and Co sub(x)N crystal structures leading to a synergistic effect of the two interfaces, and the carbon shell also increased the number of nitrogen active sites. Moreover, the integrated structure of CoNP[at]NC/NG provided high electrical conductivity and facilitated electron transfer. Furthermore, the rechargeable zinc-air battery testing of CoNP[at]NC/NG-700 revealed good performance and long-term stability. The current work provided a new pathway to design bifunctional catalysts with multiple crystal phases for energy conversion and storage.