Dynamic Coordination Engineering of Z‐Scheme (FFV)₂PdCl₂/C₃N₄ Heterojunction for Superior Photocatalytic Hydrogen Evolution

Abstract Realizing highly efficient photocatalytic hydrogen evolution reaction (HER) is a key challenge. Herein, a (FFV) 2 PdCl 2 complex is developed with dynamic coordination engineering between the Pd II site and Fluoflavin (FFV) ligands, and couple it with graphite carbon nitride (g‐C 3 N 4 ) ultrathin nanosheets to construct a novel Z‐scheme heterojunction ((FFV) 2 PdCl 2 /C 3 N 4 ). The resultant heterojunction delivers a HER activity of 648 µmol h −1 under visible light ( λ ≥ 400 nm) illumination and an apparent quantum yield up to 40.1% at 400 nm, far superior to those g‐C 3 N 4 ‐based catalysts reported previously. Mechanistic and theoretical studies reveal that the dynamic coordination between the Pd II site and FFV ligands not only significantly accelerates the electron transfer from g‐C 3 N 4 to (FFV) 2 PdCl 2 and then to the Pd II sites via a Z‐scheme mechanism, but also effectively maintain the efficacy and stability of the Pd II active sties, and thus the (FFV) 2 PdCl 2 /C 3 N 4 with a ultralow Pd‐loading amount (ca. 0.1 wt.%) exhibits the impressive activity and durability. The present dynamic coordination and structural evolution of (FFV) 2 PdCl 2 are also applicable for significantly improving the HER performance of other semiconductors, thus paving a potential way for manufacturing highly efficient and active H 2 production systems.