Structural and Phase Engineering of a Hierarchical 2D–2D Nickel MOF/Hydroxide‐Derived Ni0.85Se/NiTe2 Heterointerface for Robust HER, OER, and Overall Water Splitting

The development of a nonnoble metal-based cost-effective, efficient, and durable bifunctional electrocatalyst is crucial to achieving the goal of carbon neutrality. In this study, a structural and interfacial engineering approach is employed to design a 2D-2D hierarchical nickel MOF/nickel hydroxide-derived nickel selenide/nickel telluride dual-phase material through a single-step selenotellurization process. The rational design of highly ordered nanoarchitectures provides well-defined voids and ample pathways for ion diffusion. Furthermore, hierarchical nickel selenide/nickel telluride works synergistically at heterojunctions, providing a local ion enrichment mechanism for the catalytic process. As a result, Ni