MOF-derived MoS2@o-CoSe2 hetero-catalysts accompanied by structural phase transition for efficient electrochemical hydrogen production

Although electrocatalytic water splitting is a very promising and sustainable method for generating hydrogen as a clean energy source, the design and synthesis of stable and efficient noble metal-free catalysts faces some serious challenges. In this work, an electrocatalyst with heterostructure of MoS2 and orthogonal phase of CoSe2 (MoS2@o-CoSe2) is derived from Co-based metal organic framework (Co-MOF). The complex shows excellent hydrogen evolution reaction (HER) activity and long-term stability in alkaline medium attributed to its porous structure, ultrathin nanosheet morphology, synergistic effect of each component owing to the tightly bonded interface and optimal electronic structure after phase transition. MoS2@o-CoSe2 exhibits low overpotential of 34 mV at a current density of 10 mA cm−2 and a Tafel slope of 41 mV dec−1. These results are superior to most recently reported Mo-based and Co-based electrocatalysts. Importantly, the performance of MoS2@o-CoSe2 at high current densities is even better than that of commercial Pt/C electrode. Our results emphasize the importance of phase engineering and show that the combination of MOF with transition metal disulfides is an effective way to develop highly active and sustainable efficient electrocatalysts for water hydrolysis.