Lamella-heterostructured nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride electrodes as stable catalysts for oxygen evolution.

Zeng, Shu-Pei; Shi, Hang; Dai, Tian-Yi; Liu, Yang; Wen, Zi; Han, Gao-Feng; Wang, Tong-Hui; Zhang, Wei et al. · Nat Commun · 2023

basic_science · Level V

Where this comes from

Abstract

Developing robust nonprecious-metal electrocatalysts with high activity towards sluggish oxygen-evolution reaction is paramount for large-scale hydrogen production via electrochemical water splitting. Here we report that self-supported laminate composite electrodes composed of alternating nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride (FeCo/CeO<sub>2-x</sub>N<sub>x</sub>) heterolamellas hold great promise as highly efficient electrocatalysts for alkaline oxygen-evolution reaction. By virtue of three-dimensional nanoporous architecture to offer abundant and accessible electroactive CoFeOOH/CeO<sub>2-x</sub>N<sub>x</sub> heterostructure interfaces through facilitating electron transfer and mass transport, nanoporous FeCo/CeO<sub>2-x</sub>N<sub>x</sub> composite electrodes exhibit superior oxygen-evolution electrocatalysis in 1 M KOH, with ultralow Tafel slope of ~33 mV dec<sup>-1</sup>. At overpotential of as low as 360 mV, they reach >3900 mA cm<sup>-2</sup> and retain exceptional stability at ~1900 mA cm<sup>-2</sup> for >1000 h, outperforming commercial RuO<sub>2</sub> and some representative oxygen-evolution-reaction catalysts recently reported. These electrochemical properties make them attractive candidates as oxygen-evolution-reaction electrocatalysts in electrolysis of water for large-scale hydrogen generation.