Fe-Co-P/C with strong coupling interaction for enhanced sodium ion batteries and oxygen evolution reactions

The key issue of developing the metal phosphides based electrode material is to explore the green synthesis approach and maintain the structural stability during practical applications. Herein, we report a facile electrodeposition approach combined with subsequent thermal treatment to grow Fe-Co-P on the porous carbon membrane with Magnolia leaves as precursor (Fe-Co-P/C). The three-dimensional porous carbon frameworks as substrate provide superior electrical conductivity for Fe-Co-P/C electrodes. The strong coupling between Fe-Co-P and porous carbon framework keeps the stable electron and ion transport channels for the electrode materials in the sodium ion batteries and oxygen evolution reactions. The Fe-Co-P/C as anode materials for sodium ion batteries deliver a high discharge capacity of 464 mAh g(-1) at 0.1 A g(-1). After 500 cycles at the current density of 0.5 A g(-1), the capacity of the electrode still retain 293 mAh g(-1), which is attributed to the porous carbon framework to confine the Fe-Co-P in the composites and prevent the Fe-Co-P nanoparticles from aggregating. On the other hand, the Fe-Co -P also exhibit high-efficient performance for oxygen evolution reaction with the overpotential of 151 mV to reach the current density of 10 mA cm(-2), and the Tafel slope of 77.78 mV dec(-1) in 1.0 M KOH. Our research provides a unique carbon substrate material with hierarchical nanostructure and new design stagey for bimetallic phosphide based electrode for sodium ion batteries and electrocatalytic oxygen evolution reactions. (C) 2019 Elsevier Ltd. All rights reserved.