Electrochemical Polymerization of a Carbazole‐Tethered Cobalt Phthalocyanine for Electrocatalytic Water Oxidation

Abstract The four‐electron oxidation of water (2H₂O→O₂+4H⁺+4e⁻) is critical for artificial photosynthesis. In nature, this reaction is efficiently catalyzed by photosystem II via cooperative catalytic centers and charge transporters. However, the integration of water oxidation catalysts and charge transporters in artificial systems remains challenging. In this report, a function‐integrated water oxidation catalyst produced by the electrochemical polymerization of a cobalt phthalocyanine complex bearing carbazole moieties is described. The monomer complex, Co(czPc) (H₂czPc=tetrakis(9H‐carbazole‐9‐ethoxy)phthalocyanine), was synthesized and characterized by elemental analysis, matrix‐assisted laser desorption/ionization mass spectrometry, and Fourier transform infrared and ultraviolet‐visible spectroscopy measurements. The electrochemical polymerization of Co(czPc) was confirmed using cyclic voltammetry measurements and yielded poly‐Co(czPc) on the surface of a glassy carbon electrode. Poly‐Co(czPc) showed excellent charge‐transport ability and superior electrocatalytic water oxidation performance to that of the corresponding nonpolymeric system.