Non-noble metal high entropy sulfides for efficient oxygen evolution reaction catalysis

Designing high activity and stable oxygen evolution reaction (OER) catalysts is essential for improving the efficiency of the water splitting reaction. The high entropy transition metal sulfide (HES) catalyst will be a promising candidate for accelerating the OER due to its high intrinsic activity and excellent stability. However, the synthesis of HES by chemical methods and the investigation of the structural evolution during the reaction remain a challenging task. In this work, a HES catalyst has been synthesized by a simple thermal injection method. All elements are uniformly distributed in HES nanoparticles, which exhibit excellent activity with an exceptionally low overpotential of 263 at current densities of 100 mA·cm−2 and a low Tafel slope of 51.5 mV·dec−1. This work demonstrates the great potential of HES catalysts as OER electrocatalysts and provides new ideas for the construction and extension of this family of compounds.