Phase-dependent interfacial coupling in MoS2/CoS2 heterostructures for hydrogen evolution stability

Abstract

The stability of transition-metal dichalcogenide (TMDC) heterostructures in the hydrogen evolution reaction (HER) is often attributed to intrinsic phase robustness; however, the role of interfacial electronic structure remains poorly understood. Here, we demonstrate that the MoS2 host phase governs heterostructure durability by dictating the interfacial energy landscape in MoS2/CoS2 systems. Phase-controlled 1 T and 2H MoS2 nanoflowers were synthesized and integrated with CoS2 via a scalable two-step hydrothermal route to form well-defined heterostructures. Despite its metastable nature, the 1 T-MoS2/CoS2 heterostructure exhibits remarkable stability under acidic HER cycling, maintaining per..