Giant Internal Electric Field in Ni‐Modified Perylenetetracarboxylic Acid Supramolecule via Metal‐Coordination Engineering for Efficient Photocatalytic H 2 Evolution

Developing efficient supramolecular photocatalysts is essential for green H 2 production using solar energy, yet their performance is often limited by inefficient photogenerated charge separation. Herein, this study innovatively employs the coordination‐driven self‐assembly of Ni 2+ ions and perylenetetracarboxylic acid (PTA) to construct a Ni‐PTA supramolecular photocatalyst, achieving significantly enhanced photocatalytic H 2 evolution performance. Experimental and theoretical results confirm that Ni 2+ ions are inserted into PTA interlayers via monodentate coordination with carboxyl groups, inducing pronounced charge polarization and substantially augmenting the molecular dipole moment of Ni‐PTA. The enhanced dipole establishes a giant internal electric field (IEF) within Ni‐PTA, thereby reducing exciton binding energy and increasing charge‐separation efficiency by 4.2‐fold. Thus, Ni‐PTA exhibits excellent and stable photocatalytic H 2 evolution, with a rate of 496.7 µmol h −1 , 3.8 times higher than that of self‐assembled PTA supramolecules. Meanwhile, a notable apparent quantum efficiency of 16.5% at 420 nm is achieved, surpassing most reported supramolecular photocatalysts. Furthermore, the Ni‐PTA film sample also shows stable operation with a H 2 evolution rate of 17.7 mmol m −2 h −1 , demonstrating promising practical applicability. In summary, this work highlights that metal‐coordination engineering enhances the IEF of supramolecular photocatalysts for promoting charge separation, providing a new design strategy for efficient photocatalysts.