Molecular ladder polymer network enables scalable and robust solar water oxidation

Abstract

Organic polymers with tunable band structures and light absorption properties offer a versatile alternative to inorganic materials for solar energy conversion. However, advancing organic polymers for efficient solar water oxidation has been hindered by challenges in charge separation and transport. Here we develop a molecular strategy to achieve an apparent quantum yield of 22 % for solar water oxidation by using a ladder polymer network coupled with a FeNi catalyst. Solar irradiation of the photocatalytic network produces high-flux excited states capable for catalyst activation, generating persistent charge-separated states available for water oxidation. The network exhibits high robustness during 125-hour solar water oxidation, showing negligible decrease in the photocatalytic activity. Owing to improved charge transport, the photocatalytic network is scaled up from 1.0 cm2 to 25 cm2 without sacrificing the quantum efficiency. Our findings herald the potential of ladder polymer networks toward scalable manufacturing of high-efficiency and cost-effective organic photocatalysts.