Photoactive Conjugated Polyelectrolyte‐Ionomer Composite Coatings for Versatile Photoreactors

Conjugated polymers are promising photoactive materials for heterogeneous photocatalysis, but their limited solubility hinders the scalability in practical use. Herein, we develop polymer composites using processable conjugated polyelectrolytes and ionomers to fabricate photocatalytic thin films with visible light activity. The composite of conjugated polyelectrolytes and ionomers with identical counter anions in their side chains enables compatibility in solvents and stabilized charged states within the composite. This facilitates the development of stable coatings on diverse substrates and enhances charge separation and transport. The resulting photocatalytic thin films exhibited a 1.5‐fold increase in photocurrent response and a 7.0‐fold increase in mechanical strength compared to the pristine conjugated polymer. Photoactive coatings with polymer composites showcase the potential for synergistic photocatalytic oxidation of NADH, organic dye, and sulfide under visible light irradiation. The photocatalytic thin films are stable, versatile, and scalable for various photocatalytic reactions, showing promise for developing upscaled photoreactors.