Iron Single-Atom Anchored MoS2: A High-Performance Bifunctional Electrocatalyst for Overall Water Splitting

Abstract The commercialization of electrochemical water-splitting systems necessitates the development of electrocatalysts that are highly efficient, cost-effective and durable. Among the promising candidates, transition metal dichalcogenides (TMDs), such as MoS2, have emerged due to their theoretical hydrogen adsorption energy being close to that of platinum. Nonetheless, the sluggish kinetics of the hydrogen evolution reaction (HER) in alkaline environments and the poor oxygen evolution reaction (OER) activity of MoS2 hinder its advancement as a bifunctional electrocatalyst. In this work, Fe single-atom-doped 1T-MoS2, an advanced bifunctional electrocatalyst, was developed via a simple one-step hydrothermal synthesis route for overall water splitting. All of the as-prepared electrocatalysts exhibited a flower-like morphology with ultra-thin flakes. The optimized electrocatalyst, Fe15at%/MoS2, demonstrated superior HER and OER performance in alkaline media, requiring low overpotentials of 148 and 233 mV at 10 mAcm–2, respectively. Furthermore, an electrolyzer fabricated using Fe15at%/MoS2 as both the cathode and anode (Fe15at%/MoS2 || Fe15at%/MoS2) exhibited a cell voltage of only 1.65 V to achieve a current density of 10 mAcm–2, along with excellent stability for 200 h during overall water splitting. Hence, this study highlights the potential of single-atom catalysts supported on TMDs as high-performance electrocatalysts for large-scale water splitting, thereby facilitating sustainable hydrogen production.