Ir Nanoparticles Anchored on Metal‐Organic Frameworks for Efficient Overall Water Splitting under pH‐Universal Conditions

Abstract The construction of high‐activity and low‐cost electrocatalysts is critical for efficient hydrogen production by water electrolysis. Herein, we developed an advanced electrocatalyst by anchoring well‐dispersed Ir nanoparticles on nickel metal‐organic framework (MOF) Ni‐NDC (NDC: 2,6‐naphthalenedicarboxylic) nanosheets. Benefiting from the strong synergy between Ir and MOF through interfacial Ni−O−Ir bonds, the synthesized Ir@Ni‐NDC showed exceptional electrocatalytic performance for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting in a wide pH range, superior to commercial benchmarks and most reported electrocatalysts. Theoretical calculations revealed that the charge redistribution of Ni−O−Ir bridge induced the optimization of H 2 O, OH* and H* adsorption, thus leading to the accelerated electrochemical kinetics for HER and OER. This work provides a new clue to exploit bifunctional electrocatalysts for pH‐universal overall water splitting.