Background

The development of efficient electrocatalysts for water-splitting is crucial to meet future energy demands. Layered double hydroxides (LDHs) have emerged as promising electrode materials in alkaline medium owing to their superior electrocatalytic properties.

Methods

In this study, we report the synthesis of two-dimensional nanosheets of trimetallic cobalt-zinc-iron (Co_1-xZnFe_x) LDH via a coprecipitation method as an effective catalyst for oxygen evolution reaction (OER). We investigated the electrocatalytic activity of Co_1-xZnFe_x LDH by tuning the concentrations of Fe and Co (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5).

Significant findings

The Co_1-xZnFe_x (x = 0.3) LDH exhibited the highest OER performance, requiring only 350 mV overpotential and showing 63 mV dec⁻¹ Tafel slope to achieve a geometric current density of 10 mA cm⁻² indicates the improved reaction kinetics. The Co_0.7ZnFe_0.3 LDH nanosheets had a large surface area and many active sites, as evidenced by the double layer capacitance (C_dl) slope of 28 µF cm⁻² in a 1 M KOH electrolyte. Moreover, the Co_0.7ZnFe_0.3 LDH electrocatalysts also maintained excellent stability with a current retention of 99% over 10 h. Hence, our proposed two-dimensional nanosheets-based LDH could be a promising candidate for the development of high performance electrocatalysts for the OER.