Ultrafast room-temperature construction of hierarchical hollow rodlike nanoarrays based on amorphous NiFeCo layered double hydroxide toward enhanced oxygen evolution reaction

Abstract

Designing and constructing non-noble metal electrocatalysts with high catalytic activity for oxygen evolution reaction (OER) is a significant challenge for energy storage and conversion. Transition-metal-based layered double hydroxides (LDHs) are the most efficient OER catalysts. However, their catalytic performance and commercial application are limited by their small electrochemical active areas and poor electronic conductivity. Herein, hollow hierarchical rodlike nanoarrays on nickel foam assembled with amorphous NiFeCo-LDH nanosheets were prepared using a metal–organic framework, ZIF-67, as a sacrificial template by a facile and ultrafast ion-exchanged reaction at room temperature. The as-prepared electrocatalyst possessed a large specific surface area (397 m2/g), unique structure, fast charge transfer and abundant active sites, and thus displayed a superior performance for OER with a low overpotential of 202 mV at 10 mA/cm2, a Tafel slope of 47.9 mV/dec and long-term durability in 1.0 M KOH electrolyte. This research affords a facile strategy to rationally design high activity electrocatalysts of multi-metallic LDHs for OER.