Carbon nanotubes-interconnected heterostructural FeP/Ni2P nanospindles as efficient and stable electrocatalysts for oxygen evolution reaction

Abstract Oxygen evolution reaction (OER) is a key and bottleneck reaction in energy application. In order to improve the electrocatalytic activity and electron/mass transfer efficiency, it is necessary to develop OER electrocatalyst with optimized electronic structure, porous morphology, and high conductivity. Herein, we present a novel carbon nanotubes (CNT)-interconnected, FeP/Ni2P heterostructure-embedded nanospindles (FeP/Ni2P@CNT) as an advanced OER catalyst. Due to the effective charge transfer via electronic structure modulation in FeP/Ni2P heterostructure, superior electrical conductivity of existing CNTs network, inevitable active catalytic sites exposure by ultrafine FeP/Ni2P heterostructural-nanoparticles (~10 nm), and the porous nanostructure facilitated gas bubbles release, the FeP/Ni2P@CNT catalyst displays exceptional OER activity. In particular, the FeP/Ni2P@CNT hybrid catalyst requires only 240 mV overpotential to reach the benchmark current density of 10 mA/cm2, which outperforms the activity of commercial RuO2 and most recently reported state-of-the-art OER catalysts. This work presents a facile strategy to fabricate efficient and stable nonprecious electrocatalysts with unique hierarchical nanostructure and modulated electronic structure.