Fabrication of a Function‐Integrated Water Oxidation Catalyst through the Electrochemical Polymerization of Ruthenium Complexes

Abstract Water oxidation (2H 2 O→O 2 +4H + +4e − ) is an essential reaction for artificial photosynthesis. In nature, photosystem II efficiently catalyzes this reaction through the synergistic effect of the catalytic center and charge transporters. However, the development of artificial catalytic systems for water oxidation in which the catalytic center is surrounded by charger transporters remains challenging. Herein, a function‐integrated water oxidation catalyst was fabricated by the electrochemical polymerization of mononuclear ruthenium complexes bearing carbazole moieties. A new precursor complex, Ru(bda)(czpy) 2 ( 2 ; bda 2− =2,2′‐bypyridine‐6,6′‐dicarboxylate, czpy=9‐[2‐(4‐pyridinyl)ethyl]carbazole), was successfully synthesized and characterized by 1 H NMR spectroscopy, single‐crystal X‐ray structural analysis, and elemental analysis. Under electrochemical conditions, the carbazole moieties of 2 dimerized to form a polymeric material, Poly ‐ 2. Poly ‐ 2 exhibited an excellent charge‐transporting ability and catalyzed electrochemical water oxidation with high efficiency. Notably, nonpolymeric systems were not catalytically active, indicating that synergism between the catalytic center and charge transporters enhanced the catalytic performance of Poly ‐ 2 .