Microflower-like Co₉S₈@MoS₂ heterostructure as an efficient bifunctional catalyst for overall water splitting

The development of a distinguished and high-performance catalyst for H₂ and O₂ generation is a rational strategy for producing hydrogen fuel via electrochemical water splitting. Herein, a flower-like Co₉S₈@MoS₂ heterostructure with effective bifunctional activity was achieved using a one-pot approach via the hydrothermal treatment of metal-coordinated species followed by pyrolysis under an N₂ atmosphere. The heterostructures exhibited a 3D interconnected network with a large electrochemical active surface area and a junctional complex with hydrogen evolution reaction (HER) catalytic activity of MoS₂ and oxygen evolution reaction (OER) catalytic activity of Co₉S₈, exhibiting low overpotentials of 295 and 103 mV for OER and HER at 10 mA cm^-2 current density, respectively. Additionally, the catalyst-assembled electrolyser provided favourable catalytic activity and strong durability for overall water splitting in 1 M KOH electrolyte. The results of the study highlight the importance of structural engineering for the design and preparation of cost-effective and efficient bifunctional electrocatalysts.