Co-metal–organic framework derived CoSe₂@MoSe₂ core–shell structure on carbon cloth as an efficient bifunctional catalyst for overall water splitting

Electrocatalytic water splitting is a very promising and sustainable approach for generating hydrogen as a clean carbon-free fuel. To develop an efficient electrocatalyst for water splitting, the overpotential for this reaction must be minimized by using a capable electrocatalyst that can support the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). In this study, we prepared a unique core–shell structure, Co-metal–organic framework (MOF) derived cobalt diselenide laminated with molybdenum diselenide (MOF-CoSe₂@MoSe₂) and assessed its performance as a bifunctional electrocatalyst for the HER and OER in alkaline media. The CC/MOF-CoSe₂@MoSe₂ core–shell structure fabricated directly on a flexible carbon cloth substrate demonstrated low overpotentials (η₁₀) of 109.87 and 183.81 mV for the HER and OER, respectively, and a low voltage of 1.53 V for overall water splitting activity with an electrolyzer cell with symmetric CC/MOF-CoSe₂@MoSe₂ electrodes. The developed CC/MOF-CoSe₂@MoSe₂ catalyst had excellent stability over 24 h for OER, HER, and overall water splitting activity. These results suggest that lamination of MOF with a transition metal dichalcogenide is an effective route for developing the highly efficient and sustainable bifunctional electrocatalyst for overall water splitting activity.