Hybrid carbon nanowire networks with Fe–P bond active site for efficient oxygen/hydrogen-based electrocatalysis

Abstract

Exploring inexpensive, universal, highly active and stable electrocatalysts toward the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) is critical for developing high-performance energy conversion and storage devices. Herein, we report the synthesis of three-dimensional (3D) hybrid carbon nanowire (i.e., Fe/P/C) networks with superior ORR, OER and HER activities and stabilities, and further experimentally confirm the Fe–P bond in the networks is one of the main active sites for ORR, OER and HER for the first time. Under the optimized condition, the resultant Fe/P/C networks show better ORR electrocatalytic activity in alkaline media/comparable activity in acidic media, better durability and stronger methanol tolerance compared to those of 20wt.% Pt/C. The Fe/P/C networks also exhibit high activity with a potential of 1.56V (vs. reversible hydrogen electrode) to achieve 10mAcm−2 and a small Tafel slope of 67.1mV dec−1 for OER in 1.0M KOH. Furthermore, as HER electrocatalyst, the Fe/P/C networks need a low overpotential of 256mV to drive 10mAcm−2 in 0.5MH2SO4. These make Fe/P/C nanowire networks to be among the best non-precious metal based carbonaceous electrocatalysts for ORR, OER and HER to date.