Synthesis of a sulfur-doped CoLaLDH/MXene composite as an efficient electrocatalyst for the oxygen evolution reaction in alkaline medium†

This study aimed to develop a highly efficient and stable electrocatalyst for the oxygen evolution reaction (OER) to enhance hydrogen production through water splitting. Layered double hydroxides (LDHs) are promising OER electrocatalysts due to their low cost, tunable composition, abundant active sites, and large specific surface areas. However, their poor conductivity, propensity for aggregation, and inherent low activity severely hinder their broader practical application. In this work, a hybrid electrocatalyst CoLaLDH/MXene composite was successfully developed through a straightforward hydrothermal synthesis approach, and it was further enhanced via sulfur doping to boost its OER performance. The prepared S-CoLaLDH/MXene electrocatalyst outperformed RuO₂ and many other reported catalysts. It exhibited a low overpotential of 303 mV at 10 mA cm⁻², a Tafel slope of 57 mV dec⁻¹, and remarkable electrochemical stability. This research provides a valuable guideline for the design of high-performance LDH-based OER catalysts, and the proposed direct synthesis methodology establishes a foundation for its widespread application.