1 min synthesis of phase-pure nanocrystalline high-entropy sulphides for efficient water electrolysis

The development of noble-metal free electrocatalysts with low production cost is of utmost importance for sustainable water electrolysis. Herein, we present a fast, flexible synthesis pathway for the preparation of a variety of different medium- and high-entropy spinel sulphides of various compositions, using a non-aqueous microwave-assisted synthesis without any H2S. Nanoparticulate high-entropy sulphides containing up to 8 different metal cations can be obtained after an extremely short synthesis time of only 1 min and comparatively low temperatures of 200-230 °C. We further demonstrate the high activity of the obtained sulphides for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER).