Fe-doped CoSe2 nanoparticles encapsulated in N-doped bamboo-like carbon nanotubes as an efficient electrocatalyst for oxygen evolution reaction

Abstract

The utilization of clean and unlimited hydrogen energy is an attractive avenue to tackle the crises of energy and environmental pollution, and exploring high-active, earth-abundant and stable electrocatalysts for the oxygen evolution reaction (OER) is critical to the practicability for electrochemical water splitting. Herein, a nanohybrid with Fe-doped CoSe2 nanoparticles embedded in N-doped bamboo-like carbon nanotubes (denoted as FCS@N-CT) is prepared through simple pyrolysis followed by the selenization employing easily available raw materials for the first time. The received FCS@N-CT shows excellent electrocatalytic comprehensive properties for OER in 1 M KOH solution, comparable to and even surpassing the fresh RuO2. Specifically, it requires an overpotential of only 330 mV to deliver a current density of 10 mA cm−2, and achieves higher current density than that of RuO2 with elevating the potential over 1.652 V vs. reversible hydrogen electrode. More strikingly, FCS@N-CT exhibits a smaller Tafel slope and much better durability than those of RuO2. The remarkable electrocatalytic performance of FCS@N-CT can be ascribed to the unique nanostructure featuring abundant active sites, the favorable conductive network for rapid charge transfer, the synergistic effect between FCS and N-CT, along with the protection of FCS by carbon layers for strong robustness under catalytic conditions.